Isaiah 48:16 says, 'Come near to Me, hear this: I have not spoken in secret from the beginning; from the time that it was, I was there. And now the Lord GOD and His Spirit
have sent Me.' In the short term this verse speaks of the sending of Isaiah the prophet; in the long term it speaks of the sending of the Christ. Some interpret the phrase 'the Lord God and His Spirit' as a reference to the first and third persons of the trinity. We disagree with this interpretation. We see this phrase as a describing the mean by which God sends and empowers His prophets and His Son; that is, by His Spirit. For examble, Isaiah 59:21 says, 'As for Me,' says the LORD, 'this is My covenant with them: My Spirit who is upon you, and My words which I have put in your mouth, shall not depart from your mouth....' When the Bible uses the term 'Spirit' with reference to God, it is speaking of God in action, God working among mankind. Another example is Isaiah 61:1, which says, 'The Spirit of the Lord GOD is upon Me, because the LORD has anointed Me to preach good tidings to the poor....'
Jesus stated matter-of-factly that 'God is a Spirit' (John 4:24). There is not one Spirit who is God and another Spirit who is the Holy Spirit. According to Paul there is 'one Spirit' (Ephesians 4:4). And in Isaiah 45:5 the Lord Himself declares, 'I am the LORD, and there is no other; there is no God besides Me.' If the Spirit is anyone other than the Lord God Himself, then He is not God at all.