Was Jesus infallible?

In order to answer if Jesus Himself was infallible in His earthly ministry, we simply have to look at what the Word says of itself. Why? Well, the Word repeatedly speaks of its own inspiration and authority, and if the Word itself is infallible, then we can prove that Jesus, who is the Word, is infallible too. 

In John chapter 1 the Word says,

John 1:1 In the beginning was the Word, and the Word was with God, and the Word was God. ... 14 And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.

So, this confirms that Jesus is the Word. Now, what does the Word say of itself?

The Lord Jesus said in Matthew 5:17-18, “Not a letter or a part of a letter will pass away until all of it is fulfilled.” He said in John 10:35, “The Scriptures cannot be broken.” He said in John 17:17 in His high-priestly prayer to His Father, “Your Word is truth.”

And then you move to the apostle Paul, who probably gave us the classic text on the Bible’s witness to itself when he says in 2 Timothy 3:16, “All Scripture is inspired. All Scripture is God-breathed.”

The Bible is the Word of God. Yes, written in the words of men, but its ultimate author and source is God Himself, Who is a God of truth.

Also, in 2 Peter 1:20-21, Peter says that “The men of old spoke as they were picked up and carried along by the Holy Spirit.“

So, you have both inspired writers, but also inspired writings as well.

With this settled, I can answer that Jesus Himself, in His earthly ministry, was infallible. He was sinless and since He followed only His Father’s instructions, His choices, actions, speech, prophecy, and lifestyle were perfect too.