'It is I' in the Bible

And did He not make you one? Yet the vestige of the Spirit is in him. And what of the one? He was seeking a godly seed. Then guard your spirit, and do not act treacherously with the wife of your youth.

Ye have said, It is vain to serve God; and what profit is it that we have kept his charge, and that we have walked mournfully before Jehovah of hosts?