God's Word makes clear that once we die, we are raised again and as the saying goes "meet our maker". None of us can make ourselves sufficiently pure and holy to enter God's presence, so there is no choice but for us to be cast out. The language used to describe this in Scripture is distressing and disturbing.
But through the death of Jesus, those who believe and accept him are made righteous, able to spend eternity with God, not through their own merit but by God's grace.
Some of the stories and sayings of Scripture make it clear that we may be suprised at those who God considers worthy to be in His new eternity. But he leaves us in no doubt that if we call on the name of Jesus, admit our failings and accept his forgiveness, we can look forward with confidence to eternal life with Him.