We believe that human nature is sinful. Sin is the shortfall between normal human beings and God. Adam was warned not to disobey God, but he and his wife did. This brought sin to the world and its population. The Bible mentions this first in the Old Testament, and then it repeats the explanation in New Testament passages, like Romans 5:12-21.
As sinful creatures, we die. When death happens, humans are no longer aware of anything. We do not find any evidence for a conscious part of life remaining, or a soul going to heaven (which is God’s dwelling place). Have a read of Ecclesiastes, but particularly 9:5.
In Romans 6:23, we see that Jesus’ work gives us hope beyond death.
To become part of the wider community of brothers and sisters who share this hope, you need to believe in the Bible’s message and you then need to be baptised. Baptism follows belief, and it involves the believer being immersed in water (not christening). Mark 16:16 tells us this.
Jesus will return from heaven. He will then wake those of his followers who have died, as God has remembered them. The wait has allowed more people time to find the Gospel. See Philippians 4:6-7.
Psalm 37:23-29 shows us that the resurrection of believers is our only hope.