Genesis 7:16 says "and the LORD closed [the door] behind him." What does that mean?

"Doors" portray a powerful picture in the Bible, what are some of those ways?

The Bible compares Noah and the Ark to baptism; where, how and why?

What are the lessons from God closing the Ark door, for us today?

Is it a stretch to say that Noah is a symbol of Christ? If not, How is Noah and the Ark like Christ?