Why did John use "spirit" instead of "prophet" in 1John 1:3? (Part 1 of 2)

Individual prophets have individual spirits as pointed out in 1Cor. 14:32 which says, "And the spirits of the prophets are subject to the prophets." This is why Paul stated in 1Cor. 14:37 that if anyone thinks he is a prophet or spiritual, let him acknowledge that what he (Paul) was writing were the commandments of the Lord. This means that a prophet is recognized by the spirit in him.

For instance, the spirit in Amos was the spirit of vengeance of God. 1John 4:1 admonishes us to try every spirit to know whether it was of God before believing. And verse 2 says we can know the spirit of God if it confesses that Christ came in the flesh.

The spirit of God teaches that Christ came in the flesh, not of the flesh. The confirmation of this is in 2John 1:7, which says the antichrist is deceiving many people by teaching that Jesus did not come in the flesh.