1 Corinthians 15:14-1914 And if Christ be not risen, then is our preaching vain, and your faith is also vain. 15 Yea, and we are found false witnesses of God; because we have testified of God that he raised up Christ: whom he raised not up, if so be that the dead rise not.
16 For if the dead rise not, then is not Christ raised:
17 And if Christ be not raised, your faith is vain; ye are yet in your sins.
18 Then they also which are fallen asleep in Christ are perished.
19 If in this life only we have hope in Christ, we are of all men most miserable.
Play out a little fantasy for me. If we were to travel back in time, and learn by observation that much of the New Testament was inaccurate - that Jesus did not say half those things, and none of the disciples knew anything about Him walking on the water, but you could witness somehow from near the tomb that he had died and was risen again, there wouldn't be much problem about the rest. We would adjust to the lack of good documentation, if we had the one fact of resurrection clear.
On the other hand, if we found that the events recorded by the gospel and epistle writers were remarkably true, even the difficult bits, but it appeared that there was no evidence for resurrection no matter where you looked, then our faith would be in ruins.
That is my key answer to the fundamentalists. You are looking in the wrong place; you are defending the wrong city.