Bible Verses About Sincerity: Our service to God

Nowe therefore feare the Lord, and serue him in vprightnesse and in trueth, and put away the gods, which your fathers serued beyonde the flood and in Egypt, and serue the Lord.

But the houre commeth, and nowe is, when the true worshippers shall worship the Father in spirit, and trueth: for the Father requireth euen such to worship him.

God is a Spirite, and they that worship him, must worship him in spirit and trueth.