A response to some issues gnostics bring up...

Here is the problem. Have you done the work in Scriptures before venturing off into exposing false writings? It would make the latter vain if you don't have foundation in the former and to be saved first to know Jesus is uncreated deity, died on the cross and was resurrected for sure!

Your attitude and assumptions are incorrect regarding the first 5 books as spurious. What can be said is Moses wrote the majority of them and with some small parts that others would have contributed. This does not constitute as being spurious, but you are looking to petty excuse to reject Christ to find some flaw in that, but does that really hold water? This poses no problem at all.

These other books the Bible refer to are not included in the Bible because they are not deemed warranted for various reasons or they have some flaw in them, though not entirely false. Only books perfectly correct are included in the 66 books of God's Word. Again, this poses no problem, and still requires you to have strong foundation in the Scriptures and be saved first before in vain venturing off into other books. Are you not thus lacking in this approach? The flesh wants to scurry around in everything else while still not be saved, thus it is a real choice you have made to go to hell.

The Bible uses the son of man in several instances which predate the book of Enoch, and even if the book of Enoch references the Son of Man, how does that change anything?

What matters is how the Bible wants to present the term Son of Man because the Word of God is being expressed in its fullness. Daniel speaks of one like the Son of Man coming on the clouds. This would be the same Son of Man then is referred to the coming Messiah, "behold, [one] like the Son of man came with the clouds of heaven, and came to the Ancient of days, and they brought him near before him" (Dan. 7.13).

Jesus' using the title "Son of Man" in reference to His resurrection predictions (Mark 8.31; 9.31; 10.33-34) weighs favorably for its authenticity and significance. The "principle if dissimilarity" is in play here. While the Jews never referred to the suffering Messiah (Dan. 7.13-14) as the Son of Man, so too do the epistles never speak of the Son of Man.

Therefore, the fact that Jesus points out the Son of Man concerning himself seems quite authentic. And there is multiple attestation of Jesus' resurrection in many verses in Matthew 12.38-40; 16.1-4,21; 17.23; 20.19; Mark 8.31-32; 9.31; 10.33; Luke 9.22; John 2.18-21. Cf. Mark 14:58; Luke 11.29-30.

What is also interesting is that the disciples were shocked about a resurrection of Jesus because they did not expect it (Mark 8.31-33; 9:31-32; 14:27-31; Luke 24.13-24). Their first conclusion was someone stole the body (John 20.2, 13-15). They thought too the women were telling an idle tale (Luke 24.10-12). Even when viewing the tomb they didn't know what to think (John 20.9). Thomas simply refused to believe like you (John 20.24-25).
The apostles were highly respected, so it is unlikely they would make up a term for Jesus being the Son of Man, because it would put them in a bad light. This is what is called the "principle of embarrassment". This is strongly in favor of Jesus predicting His resurrection.