Answer: In John 3:13 Jesus says to Nicodemus, “No one has ever gone into heaven except the one who came from heaven–the Son of Man.” This verse is somewhat difficult to interpret and is often misunderstood. It is also frequently used by those who want to find contradictions in the Bible.
We must keep the verse in context. In verses 10-12, especially, we see that Jesus is talking about His authority and the validity of His teaching. Jesus tells Nicodemus that He has been teaching what He knew firsthand: “We speak of what we know, and we testify to what we have seen” (verse 11). Then, in verse 13 Jesus explains why He is uniquely qualified to teach of the kingdom of God—namely, because He alone came down from heaven and possesses the knowledge to teach people about heaven. Jesus alone has seen the Father, and He alone is qualified to declare God and make Him known (John 1:18.).
The gist of John 3:13 is this: “None of your earthly teachers can really teach you about heaven, because none of them have actually been there. However, I have been there. In fact, it is My home. I have come to you from heaven, and I have brought with Me experiential knowledge of that place. My testimony carries weight; I can tell you the truth about salvation.” The NLT brings out the meaning well: “No one has ever gone to heaven and returned. But the Son of Man has come down from heaven.”
In claiming a heavenly abode, Jesus was claiming deity. Nicodemus himself had already admitted that Jesus was extraordinary when he said, “We know you are a teacher who has come from God” (verse 2).
Jesus was not teaching that no one had ever gone to heaven before. Obviously, the Old Testament saints had gone to heaven (or paradise) when they died (Mark 12:26-27), and Enoch and Elijah had been taken there without dying (Genesis 5:24; Hebrews 11:5; 2 Kings 2:11). Rather, He was teaching that, of all rabbis, He had the best credentials. Jesus has direct contact with heaven; He is an expert on the subject.
Source
The Bible Guild
What if Jesus meant every word He said?