1 Corinthians 11:29 - 30
NKJV - 29 For he who eats and drinks in an unworthy manner eats and drinks judgment to himself, not discerning the Lord's body. 30 For this reason many are weak and sick among you, and many sleep.
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
When the Bible refers to sleep most of the time it is speaking about death.