DID CAVEMEN GO TO HEAVEN?

Cavemen refer to "prehistoric" or "Neanderthals".  Prehistoric refers to "before written records".  So, did Cavemen know GOD or not?  What happened to the people who lived and died, before the birth and death of JESUS, before the Bible was written? How did Cain and Abel know to bring offerings to GOD (Genesis 4:3), how would Noah have known clean from unclean animals (Genesis 7:2)?  Didn't all of this happen before the Bible was written?  Apparently men knew of GOD before the Bible was written.  Cavemen?  We aren't descendants of apes, or as in any evolutionary process, where the originating species disappears.  The Bible talks of the "original creation" of man, Adam and Eve, in the Garden of Eden; not men living in Caves!  We read about the devastation after a tsunami; I wonder if the "Great Flood" left even more Devastation where caves were the only source of shelter?  And what about those already dead?  1 Peter 4:6, "For this is why, the Gospel was preached even to those who are dead, that though judged in the flesh the way people are, they might live in the SPIRIT the way GOD does."  Everyone will, or has, experienced the Presence of CHRIST and the GOSPEL, and may or may not accept or reject JESUS CHRIST   as their SAVIOR!  DID CAVEMEN GO TO HEAVEN?