'Spirit' in the Bible

So death came to Saul because of the sin which he did against the Lord, that is, because of the word of the Lord which he kept not; and because he went for directions to one who had an evil spirit,

Then the spirit came on Amasai, who was chief of the captains, and he said, We are yours, David, we are on your side, O son of Jesse: may peace be with you and peace be with your helpers; for God is your helper. Then David took them into his army and made them captains of the band.