Why are there so many contradictions in the Bible? In Matthew 10:34, Jesus says: Think not that I am come to send peace on earth: I came not to send peace, but a sword. Yet, in Matthew 26:52 he then says: Then said Jesus unto him, Put up again thy sword into his place: for all they that take the sword shall perish with the sword. Is it merely a representation of Jesus’s divided nature? As both fully human and fully divine, we assume that he also possesses all of our human flaws. Does this mean that Jesus has memory loss or was he suffering from dementia? Is the Lord just as flawed as us mortals?
At times, the Bible can seem to present various “difficulties” or “contradictions”. However, careful reading and examination of the Bible can quickly clear up these “difficulties” and “contradictions”. Keep in mind that every word of the Bible and the entirety of the Bible is inspired of God (2 Tim 3:16), and that the Bible is inerrant and infallible (it cannot err or fail in its teaching). I cover the inspiration, inerrancy, and infallibility in Part 1 of my series on Essential Bible Doctrines). Two books I highly recommend reading when it comes to understanding and resolving Bible difficulties are R.A. Torrey’s Difficulties in the Bible and David O’ Brian’s Today’s Handbook for Solving Bible Difficulties.
When it comes to Bible interpretation, it is important to keep in mind the context surrounding any Bible passage. Any passage of Scripture can be isolated to be used as a “proof text” for any interpretation, whether biblically valid or invalid. As my Bachelor-level Hermeneutics professor Dr. J.B. Hixon used to say: “A text without its context is a con”. Context is key to understanding and interpreting any biblical passage. Understanding the historical context and literary/grammatical context are the two main pillars for solid biblical interpretation. One of the best books to read on this subject is Roy Zuck’s Basic Bible Interpretation. When reading the Bible, I also recommend owning a couple of solid commentaries which can help shed light on difficult to understand passages. While Bible commentaries are not inspired of God and should not be given equal authority with the Word of God itself, the Lord has blessed us with given biblical exegetes and expositors who have shed insight and understanding on biblical passages. Two good single volume Bible commentaries which are affordable are MacArthur and Moody, and John G. Butler offers one of the best multi-volume Bible commentaries if you need solid biblical exposition without being overly technical or academic.
To answer your question with regard to Matthew 10 versus Matthew 26. Matthew 10 presents Jesus speaking in the context that during His first advent to the earth in His incarnation, His ministry would stir up opposition and hostility against Him and His disciples, even to the point where His opponents sought to (and succeeded in) killing Him and later killing many of His disciples. The “sword” used in this instance is not a literal sword, and Jesus was not advocating that He and His disciples go around Jerusalem swinging swords at individuals. The “sword” used here is a metaphor, which is figurative language to denote that the first advent of Jesus would bring opposition and hostility against Him to the point of His being crucified. Roy Zuck does an excellent job explaining figurative language in his book.
In Matthew 26, the context is the garden where Jesus was being arrested to be led away to be crucified. Peter impulsively pulls out his sword to begin attempting to injure or kill those arresting Jesus to the point where he cuts off the ear of the high priest’s servant. Jesus rebukes Peter and informs him not to use physical violence against those for a multitude of reasons. One reason is that Jesus is fulfilling the mission of God the Father by dying on the cross for the sins of mankind. Second, Jesus also alludes to the biblical law of capital punishment in his message to Peter. Lastly, Jesus can at anytime invoke heavenly defense in which he wouldn’t need the swinging of Peter’s sword to defend Him. He chose not to invoke this heavenly defense in order to fulfill the mission of God the Father mentioned in the first reason.
The passages of Scripture you mentioned are not a result of a divided nature of Jesus, but rather two different contexts, plus Jesus speaking in figurative language in the first context. In terms of the nature of Jesus, I go into the Hypostatic Union well in Part 2 on my series on Essential Bible Doctrines. While Jesus is both fully God and fully man, He was not a flawed man because He did not possess a sin nature as one being born of a virgin. Jesus did not have memory loss in these two incidents, nor was He suffering from dementia. Jesus was fully God and fully man and the two natures were without mixture in the person of Jesus (the Hypostatic Union), bur Jesus was also without a flawed, sin nature since He was also born of a virgin. Had Jesus had a sin nature or was flawed in any form as we are, then He could not have been the sinless sacrifice who died on the cross for our sins.
Update: First Fruits of Zion (a Messianic Jewish ministry, Messianic Jews are Jewish believers in Jesus Christ as the Messiah) has recently released an article concerning the sword passage. Our readers can access the article by clicking here. First Fruits of Zion offers some interesting articles of some New Testament passages, as they offer a thorough examination of the first-century Jewish context that the disciples and early church would have understood these passages.