'Enter' in the Bible

Nicodemus says to him, How can a man be born being old? can he enter a second time into the womb of his mother and be born?

Jesus answered, Verily, verily, I say unto thee, Except any one be born of water and of Spirit, he cannot enter into the kingdom of God.

I am the door: if any one enter in by me, he shall be saved, and shall go in and shall go out and shall find pasture.