In 1 John 4, John wrote,

1 John 4:1 Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world.
2 Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God:
3 And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.

Many say Jesus was a created being, but Scriptures say that he was God the Son who became man:

Matthew 16:13 When Jesus came into the coasts of Caesarea Philippi, he asked his disciples, saying, Whom do men say that I the Son of man am?
14 And they said, Some say that thou art John the Baptist: some, Elias; and others, Jeremias, or one of the prophets.
15 He saith unto them, But whom say ye that I am?
16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God.
17 And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven.

Jesus in the flesh amened Peter's words which he received from the Father, "Thou art the Christ, the Son of the living God." God was His Father, and He was God, as testified to by John:

John 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.

So, Jesus Christ was God come in the flesh. I've always liked the following quote by Merrill F. Unger and post it to end this section.

Quote Concerning Jesus Come In The Flesh:

Demons In The World Today
Chapter 8: Demons and False Religions/155-157
Merrill F. Unger, Th.D., Ph.D.

  The Apostle John presents the revelation that demonism is the impelling power that propagates false doctrine. "Beloved, believe not every spirit, but prove the spirits, whether they are of God, because many false prophets are gone out into the world" (1 John 4:1). A spirit may be believed, rightly or wrongly, when the "prophet" brings a message from the invisible spirit. The real speaker behind the prophet is either the Spirit of God, the omniscient Teacher, or a demon spirit or spirits. "The Spirit of truth" leads into "all truth," and speaks through the true man of God and teacher of sound doctrine (John 16:13). Demonic spirits under Satan, "the spirit of error" (i John 4:6), speak through the cultist or false religionist to disseminate erroneous doctrine and foster heresy.

  God's "beloved" are often extremely naive about satanic guile, and the Apostle John singles them out for warning, since all such children of God are the special targets of Satan. They are those whom Satan would like to trap in some error, snare in some cult, and saddle with some fanatical view or flagrant heresy, all in the name of alleged truth and spirituality.

  The acid test to differentiate true religion from false religion. The Apostle John urges God's "beloved" not to believe "every spirit," but to "try the spirits" in the sense of putting them to the acid test of the Word of God (cf. 1 Corinthians 12: 10). Unless this caution is strictly followed, God's people stand in peril of being taken in by demon-energized false prophets who have "gone out into the world" to start Christ-denying cults.

  In the dearest terms, John centers the test in the glorious Person and finished redemptive work of our Lord Jesus Christ. "Hereby know ye the Spirit of God" -- this is the intent of the doctrinal test, to recognize the Holy Spirit as the omniscient, sole, and all-sufficient Revealer of truth, and to recognize his truth amid the clamor of alien voices energized by "spirits not of God." These demon spirits speaking through false teachers pervert or distort to whatever degree they are able the full truth of who Jesus Christ is and what he accomplished by his death and resurrection. Only the Holy Spirit can confirm the reality of Christ's Person and finished redemptive work to a person and save him from the god of this world.

  "Every spirit," that is, every witness who speaks by the inspiration of the Holy Spirit, "confesseth" (freely and readily recognizes the fact) that "Jesus Christ is come in the flesh." This involves the confessing of a twofold truth: (1) that Jesus is the Redeemer of men; (2) "he is come in the flesh"; this means he was "the Son of the living God" (Matthew 16:16; John 6:69; Hebrews 1:2, 5; 1 John 4:15), the predicted virgin-born "seed of the woman" (Genesis 3:15), the preincarnate Word, who was "with God and was God" (John 1:1), who became man (John 1:14) -- God and man in one Person, Emmanuel, or God with us (Matthew 1:18-25).

  The confession that "Jesus Christ is come" (eleluthota, a perfect "having come," not a mere past historical fact but present and continuing in its blessed effects) to earth in the "flesh" also asserts our Lord's real humanity, both his sinless, unglorified human body before his death and his resurrected and glorified human body presently at the right hand of the Father. This is the pledge and guarantee that the body of every believer will be glorified as his is (1 John 3:1-3).

  Our Lord's "flesh" (true humanity) implies his death for us, for only by God's becoming man could he die (Hebrews 2:9, 16). Moreover, his death implies his love for us (John 15: 13). To deny the reality of Christ's humanity, therefore, is to deny his love. This is what every spirit does who does not acknowledge Jesus in the flesh. Such a spirit "is not from God; it is the spirit of Antichrist of whose coming you have heard. Right now he is in the world" (1 John 3:3, Berkeley).

  In this unambiguous manner the Apostle John gives us the acid test for differentiating false religions from the true and the Holy Spirit from demon spirits. Together with the Apostle Paul (1 Timothy 3:16-4:2), the Apostle John gives God's criterion for judging between the true and the false in the complex realm of religions. Deception will surely engulf people who follow man's voice instead of God's and who ride with ecumenical trends that depreciate God's Word and approve false shepherds within the professing church.

[End Of Unger Quote]