The Watchtower Society of the Jehovah's Witnesses claims to be the "True Faith." Lets see if it meets the qualifications:
2 Cor. 13:5 "keep testing whether you are in the faith, keep proving what you yourselves are or do you not recognize that Jesus Christ is in you unless you are disapproved (disqualified)" See your interlinear, the words "union with" which are in the NWT do not exist in the original Greek manuscripts.
Based on this scripture alone, the Watchtower is "DISQUALIFIED."
You "must be born again” by Christ's Spirit.
Rom 8:8-9 "those who are in the Flesh CANNOT please God. But you are not in the Flesh but in the Spirit, if indeed the SPIRIT OF GOD dwells in you. But if anyone does not have CHRIST'S SPIRIT, this one does not belong to Him.
Romans 9:8 That is, They which are the children of the flesh, these are not the children of God: ...
John 3:6-7 That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. Marvel not that I said unto thee, Ye must be born again.
John 1:11-12 He (Jesus) came unto his own, and his own received him not.  But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name:
Romans 10:9-10 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.  For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
1 John 5:12-13 He that hath the Son hath life; and he that hath not the Son of God hath not life.  These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God.
Again, the Watchtower, a child of the "Flesh" who refuses to believe that you must be born again by the Holy Spirit is "DISQUALIFIED!" They refuse to bow their knee and confess that Jesus Christ is Jehovah God, which is the doorway to eternal life by which the worshipper then receives the gift of the Holy Spirit dwelling within the believer!
1 Cor 6:19 "Do you not know that your body is a temple of the Holy Spirit who is IN you, whom you have received from God?”
2 Tim 1:14 “...The Holy Spirit which is dwelling In us.
Rev 3:20-21 Jesus says "Look! I am standing at the door and Knocking. If anyone hears my voice and opens the door, I will come Into him and dine with him and he with me. To the one who conquers I will grant to sit down with me on my throne, even as I conquered and sat down with my Father on His throne.”
(Please see the interlinear, the word "House" Is not in the original transcripts)
SUMMARY: How do you know if you are in the Faith?
1. Jesus Christ is in you (2 Cor. 13:5}
2. The Spirit of God (Christ's Spirit) dwells in you (Rom. 8:9)
3. The Holy Spirit dwells in us (2 Tim. 1:14).
The fullness of the Godhead dwells in you! 1. Jesus Christ, 2. the Father and 3. the Holy Spirit!
How do you enter the faith? Believing in Jesus and confessing Him as Lord.
(Rom. 10:9-10) Opening your heart and asking Jesus to come in (Rev. 3:20)
Verily, verily, I say unto you, He that entereth not by the door into the sheepfold, but climbeth up some other way, the same is a thief and a robber. But he that entereth in by the door is the shepherd of the sheep.
I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture.
Are YOU "in the faith?' The thief and robber will keep you from entering through the door, by teaching you that the Son fo God is an angel who should not be worshipped!
Matthew 23:13 But woe unto you, scribes and Pharisees, hypocrites! for ye shut up the kingdom of heaven against men: for ye neither go in yourselves, neither suffer ye them that are entering to go in.