'Therein' in the Bible

Verily I say to you, Whosoever shall not receive the kingdom of God as a little child shall in no wise enter therein.

but he saw also a certain poor widow casting therein two mites.

for righteousness of God is revealed therein, on the principle of faith, to faith: according as it is written, But the just shall live by faith.

Let each, wherein he is called, brethren, therein abide with God.