1. Inspired by Tetra's suggestions, I would like to have been a fly on the wall the moment when homosapien evolved. You know - many tens of thousands of years ago, a process that hebrew scripture authors chose to symbolically represent as the story of Adam and Eve, never thinking for one moment that evenually some folks would actually seriously believe these were two real people created out of nothing, as if by magic...
2. I would like to have been a fly on the wall when one of the authors of one of the NT scriptures penned the original. I would then have the final bit of proof that the originals, just like 100% of all ancient manuscript copies in existence, contained Kyrios (Lord) throughout, and never even once the tetragrammaton.
3. Finally, to witness the transfiguration of Christ in Jerusalem (yes I'm 98% a believer) - ie when that body 'of dust' suffered physical death was transfigured finally and completely into its spiritual substratum. To witness that prototype of the destiny of the whole cosmos, transfigured from decay and darkness into glory and everlasting light. Then I could be 100% a believer and no longer a doubting Thomas.