Pope Pius XII defined a dogma for the Roman Catholic Church on November 1, 1950. He stated:
“we pronounce, declare, and define it to be a divinely revealed dogma: that the Immaculate Mother of God, the ever Virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory” 
History like the History Channel
For the first three centuries of Christian history, we have no record of any eyewitnesses seeing Mary being bodily assumed into heaven. In the third century, a book titled the book of Mary’s repose, that produced something similar to what Pius XIII made dogma. However, this work was widely seen as unorthodox and is often referred to as a “Heterodox apocryphon”.  Roman Catholic, Father Mateo, speaking about the assumption of Mary admits:
Many writers have noted the absence of historical record for the Assumption of Mary. Explicit historical and, indeed, liturgical testimony for the belief is lacking. . .” 
Roman Catholic Scholar Ludwig Ott tells us
The idea of the bodily assumption of Mary is first expressed in certain transitus-narratives of the fifth and sixth centuries”
This is a significant admission. The Transitus-narratives were forgeries from people who would sign the name of Church Fathers on their documents to try to pass their ideas to the populace. As John Haldane notes:
Pseudo-John the Theologian The Dormition of the Holy Mother of God (fifth century); Pseudo-Melito of Sardis, The Passing of Blessed Mary (fifth century); Pseudo-Cyril of Jerusalem, Discourse on Mary the Mother of God (fifth/sixth century); Pseudo-Evodius of Rome, Discourse on the Dormition of Mary (sixth century); Theodosius of Alexandria, Discourse on the Dormition of Mary (sixth century); and Pseudo-Joseph of Arimathea, The Passing of the Blessed Virgin Mary (seventh century)” 
Needless to say, the doctrine found it’s way into the Church. So the assumption of Mary comes not from the Bible or the Church Fathers but instead a heterodox third century apocryphon. Michael Hesemann notes:
The exact circumstances of her death and her Assumption, on the other hand, remains a mystery forever. It is not possible to prove it by the methods of historiography and archaeology. 
Historian Jaklov Pelikan rightly notes:
So traumatic was the effect of the dogma of papal infallibility that the pope did not avail himself of this privilege for eighty years. But when he finally did, by proclaiming the assumption of the Blessed Virgin Mary on November 1, 1950, he confirmed the suspicions and misgivings of the dogma’s critics. Not only is Scriptural proof obviously lacking for this notion, but the tradition of the early Christian centuries is also silent about it” 
Rome seems content on defining dogmas as they see fit, with no historical backing and chuck it up to “it was revealed to me”. How is this any different than a Charismatic saying something pulled out of thin air and when questioned, declare “God told me it.”? Anyone can say “God told me X” the only difference is the Roman Catholic Church, the Pope in particular, has the authority to make X dogma. Lastly, read carefully the words of Roman Catholic Scholar Richard P. McBrien who admits
From the beginning of the sixth century various churches celebrated Mary’s bodily assumption into heaven. The belief originated not from biblical evidence nor even patristic testimony, but as the conclusion of a so-called argument from convenience or fittingness. It was ‘fitting’ that Jesus should have rescued his mother from the corruption of the flesh, and so he ‘must have’ taken her bodily into heaven”
In conclusion of our historical inquiry into the assumption, we see that Historians and Catholic Scholars alike admit that the assumption of Mary is not from patristic testimony or biblical evidence. Speaking of Biblical evidence, that’s where we are going next. An Assumption Scripture Doesn’t Make This should be obvious since even prominent Catholics admit it’s not biblical. For example, Roman Catholic Apologist Karl Keating states:
Still, fundamentalists ask, where is the proof from Scripture? Strictly, there is none . . . The mere fact that the Church teaches the doctrine of the Assumption as something definitely true is a guarantee that it is true” 
Despite the fallacious appeal to authority and the circular reasoning, the main thing to take away from this is that Catholic apologists are content in believing a dogma with no biblical evidence. But for the ones that do, I will address the verses here.
“And tombs were opened, and the bodies of many saints who had died were raised.(They came out of the tombs after his resurrection and went into the holy city and appeared to many people.)” (Matthew 27:52-53 NET)
Catholic scholars such as Ludwig Ott suggest:
According to the more probable explanation, which was already expounded by the Fathers, the awakening of the ‘saints’ was a final resurrection and transfiguration. If, however, the justified of the Old Covenant were called to perfection of salvation immediately after the conclusion of the redemptive work of Christ, then it is possible and probable that the Mother of the Lord was called to it also” 
The problem with this is two-fold. First, Ott’s claim that it is probable that Mary was called into this saint resurrection is a logical fallacy called “Proof by example” or inappropriate generalization. The form of the argument given by wikipedia perfectly illustrates how Ott’s statement fits this fallacy.
I know that x, which is a member of group X, has the property P.Therefore, all other elements of X have the property P.
Small x = Mary Big X = Saints P= Resurrection. Essentially, Ott is saying
“I know, that since Mary is a saint, she has the same properties as a saint who was resurrected in Matthew 27 and even though she wasn’t mentioned, she was probably there.”
But such conversations are superfluous, since many Catholics unashamedly admit it’s not a biblical idea.
A Response to an Intelligent Defender
A popular Catholic website which I actually like, due to its intellectual nature in it’s critiques of Protestantism and it’s defense of Catholicism and thought-provoking articles did an uncharacteristically bad post when it came to defend the assumption of Mary. That is to be expected, no matter how intelligent you are, defending the indefensible is a tall order. He lays out 5 reasons why we should believe in the assumption. The First is “There is no positive argument against the assumption” With all due respect, how is this not an argument from ignorance? (Ignorance = lack of contrary evidence). I’d first respond to why exactly you need positive evidence in order to determine a proposition is false. If I say that an invisible Legolas from Lord of the Rings is watching me type this to you, you would not need positive evidence to disprove my claim. He goes on to suggest that
Nothing in the dogma of the Assumption of Mary is contrary to anything taught in Christianity.
Yeah, the problem is we don’t want people inventing dogma that is ostensibly not contradictory to Christianity. If the assumption was a stand alone doctrine, It would be theological speculation at best, but because of it’s connected doctrines, IT IS in contradiction to already established Christian doctrines. Because you can’t really have the assumption of Mary without the immaculate conception and Mary’s sinlessness, you do run into direct biblical contradictions such as Romans 3:23. (Yeah, I know Jesus didn’t sin, because he’s included in the “God” part of that verse that you’re falling short of.) His second/third reason is that the Bible teaches that Mary is the Ark of the New Covenant. This is a common thing for Roman Catholics to say, but just how exegetically sound is this? First, he compares the actual ark of the covenant in 2 Samuel 6 and Mary in Luke 1 because of the English translation of “arose and went”, as if the similar verbiage would build his case and draws various parallels between the two. This argument isn’t new, many Catholic apologists over the years have argued that Mary is this ark of the new covenant. This exact argument is actually argued by Scott Hahn in his 2006 book:
“David’s travels as he brought the ark of the covenant to Jerusalem. The story begins as David ‘arose and went’ (2 Sam 6:2). Luke’s account of the visitation begins with the same words: Mary ‘arose and went’ (1:39)” 
Eric Svendsen brilliantly points out about this argument
We are told that Mary is paralleled with David (both ‘arise’ and ‘set out’), while other times Mary is paralleled with the Ark. Moreover, the statement of David in 2 Sam 6:9, ‘How can the ark of the LORD come to me?,’ changes the parallelism from Mary/David to David/Elizabeth . . . The fluctuation of the parallelism from Mary/Ark to Mary/David to David/Elizabeth to Elizabeth/Obed-Edom seems too capricious to be valid, and is for that reason alone rightly rejected by most scholars” 
Also, the parallelism is absurd. A lot of people get up to go somewhere, this parallelism could apply to almost anyone even if in the same destination. I will provide you with a real life example from me.
- I arose and took a plane to see a person in Florida.
- 2 years later, I arose and took a plane to see a person in Florida.
- Therefore, I saw the same person.
Now, you could say there are enough similarities to conclude that the person I saw the first time is the person I saw the second time. If we are dealing in probabilities, maybe, but it can’ be necessarily so. In my case, it wasn’t. There are also a lot of places in the Bible where similar language is used such as in Matthew 9:9, Mark 1:31, Luke 4:38, Acts 8:26 etc.) He then points out that they both spend three months in Judah. However, as Scholar Leon Morris points out
“The hill country of Judah ‘Judah’ not Judea (emphasizes the connection with the great patriarch) does not locate the home of Zechariah and Elizabeth with any precision, but it does make it clear that they were country folk. Attempts to identify the place have not been successful” 
Luke 1:39 says Mary was in the hill country in Judah. 2 Samuel 6:10 says David went to “the house of Obed-edom the Gittite.” Old Testament scholar Ronald F. Youngblood notes about the location:
“…probably located ‘somewhere on the southwestern hill of Jerusalem” 
This is a pretty large land Mary is presumably at. But David travels to the southwestern hill of Jerusalem; Jerusalem itself being a small city. The obvious conclusion is that it improbable to say that these were the same exact locations and dishonest to claim so with certainty. The fourth reason is “Mary reigning with Christ is extremely biblical” He cites this scripture in his defense:
“…If we have died with him, we will also live with him;if we endure, we will also reign with him;… ( 2 Timothy 2:11-12a ESV)
But before he cites this passage, he scoffs at the idea that God’s glory belongs to himself. It’s not as if the Bible says exactly that. Oh wait, it does.
“I am the LORD; that is my name; my glory I give to no other, nor my praise to carved idols.” (Isaiah 42:8 ESV)
But back to his view of 2 Timothy 2. There is a disconnect with his interpretation. He interprets “reign with him” to the conclusion that we obtain in some way or another, or at least share in God’s omni attributes. The idea that saints can intercede for billions of prayers at a time, Mary is to be a refuge for sinners etc. However, it is a logical leap to assume that our reigning with him therefore makes us share in his omni attributes. Ligonier Ministries put out an article on this particular verse and brings up an excellent point.
In some ways, Christians share in the anointing that Jesus enjoys as the Christ, the “anointed one” (Acts 10:34–43; 1 John 2:20, 27). Therefore, every believer fulfills the prophetic, priestly, and kingly roles for which our Savior has been anointed. In a sense, we are all prophets called to proclaim God’s Word, priests ordained to offer ourselves as sacrifices, and kings enthroned to war against the Lord’s enemies and help expand His kingdom (Matt. 28:18–20; Rom. 12:1–2; Rev. 17:1–14). Yet we do not share in Christ’s kingly office only in the sense that we fight against the Devil and his minions; rather, we also reign with Jesus over creation.
You see, reigning with Christ is a beautiful truth that we share in Jesus’s anointing, however, this does not make us God-men.(Reductio Ad Absurdum) neither does it make Mary a co-mediatrix.(1 Timothy 2:5)
His last reason for believing in the assumption of Mary is “There’s Good Direct Biblical Reason to Believe in the Assumption” He cites Revelation 11:9-12:2 about the woman clothed with the sun, the problem of course is this relies in his reason number 2, which we have seen is not as exegetically probable as we were led to believe. Regardless, I will do what he was complaining about in reason 1 and will provide positive evidence for who the woman clothed with the sun is in Revelation 11-12. (spoiler alert: It isn’t Mary) Matthew Henry in his commentary on Revelation 12 states:
The church, under the emblem of a woman, the mother of believers, was seen by the apostle in vision, in heaven. She was clothed with the sun, justified, sanctified, and shining by union with Christ, the Sun of Righteousness. The moon was under her feet; she was superior to the reflected and feebler light of the revelation made by Moses. Having on her head a crown of twelve stars; the doctrine of the gospel, preached by the twelve apostles, is a crown of glory to all true believers 
The dragon persecutes the rest of her offspring, which of course, must be metaphorical for the catholic, since she is a perpetual virgin to them. This would have to mean that she is the Mother of the Church, so their argument here is at least internally consistent. However, the imagery of the woman in labor is heavily paralleled in Isaiah 26:16-18, 54:1-2, and 66:7-9 which are meant to mean Israel. The Church is the New Israel, so it seems obvious that while there might be an allusion to Mary in Revelation 12, the more historical view and biblical view holds more explanatory power. I can see how someone might interpret Revelation 12 as Mary, however Historians and even other Catholic scholars and historians seem divided on this issue. Giovanni Miegge states:
“The modern Mariologists like to turn to [Revelation 12], seeing in it an allegory of the Virgin Mary. But whatever can be thought of their interpretation, it is a fact that none of the early interpreters before the end of the fourth century see the Virgin Mary in the woman of the Revelation. They all understand her to be the Church and so they continue to make most of their interpretations in the following centuries. Ticonius is the first to suggest the Marian interpretation” 
Luigi Gambero thinks it was first found in Epiphanius, strange as that may seem as he was against excessive devotion to Mary:
The identification of the woman of the Apocalypse with the Virgin Mary is interesting. It may be the first Marian interpretation of the scriptural text” 
Juniper B. Carol, O.F.M. thinks it was Tychonius (370 /390):
“Tychonius, a lay theologian among the Donatists, independent enough to be excommunicated by his own sect, seems to have identified Mary with the woman of Apoc. 12, and to have spoken of a ‘great mystery’ in her regard.” 
Catholic Scholar Raymond Brown seems to agree with the Protestant Interpretation when he states:
“The woman clothed with the sun, having the moon under her feet and on her head the crown of twelve stars, represents Israel, echoing the dream of Joseph in Gen. 37:9 where these symbols represent his father (Jacob/Israel), his mother, and his brothers (the sons of Jacob who were looked on as ancestors of the twelve tribes) 
Even in the New Catholic Bible Commentary notes we find
the woman adorned with the sun, the moon , and the stars (images taken from Gn 37, 9-10) symbolizes God’s people in the Old and the New Testament. The Israel of old gave birth to the Messiah (5) and then became the new Israel, the church, which suffers persecution by the dragon (6. 13-17); cf Is 50, 1;66, 7; Jer 50, 12. This corresponds to a widespread myth throughout the ancient world that a goddess pregnant with a savior was pursued by a horrible monster; by miraculous intervention, she bore a son who then killed the monster” 
So, taking this all together, the lack of historical backing, exegetical uncertainty, and a more probable interpretation provided that even Catholic Scholars agree with, I present this as a cumulative case on why the assumption of Mary is just that, an assumption, and a faulty one at that.
 Raymond E. Brown, An Introduction to the New Testament (New York: Doubleday, 1997), p.790
 The New Catholic Answer Bible (Wichita: Fireside Catholic Publishing, 2005) p. 1384