`The Faith` is believing
→ that Jesus is the personification of God
→ that Jesus died and rose from the dead under His own power
→ that faith in Jesus alone brings salvation
→ that we receive His Holy Spirit when we ask for Him in the name of Jesus
→ the Holy Spirit in us is Christ in us
The Jews denied the deity of Jesus. Many of the early believers were Jews. Their people, especially their priests and rabbis, tried to dissaude Jewish believers from believing in Christ`s deity. They were told that Jesus was just a great prophet, teacher and healer - that He was not God.
Paul`s Thorn In The Flesh was likely a group of Jewish men that followed him around undermining the work that he was doing to spread the Gospel of Jesus Christ by denying the deity of Jesus.
The core of the Gospel are the points listed above.
The Jews could not turn loose of their YHVH concept. They did not accept Jesus as YHVH in the flesh.
The concept of the trinity came out of the pressure to deny Jesus as YHVH, demoting Him to sonship only. Once the Christians were convinced of the trinity, the Jews then mocked them as polytheists, as did the Muslims who came along later.
The Faith is all about the Lord Jesus Christ - who He is and what He has done including His omnipotence as stated in .
The `corrupt faith` is any belief system that detracts from the one and only God whose name is Jesus.
True believers still contend for `the Faith` as there are many people who deny the supremacy of Christ Jesus in favor of some other deity who they can pray to and enter the kingdom by.
Lastly, to be a true believer in Christ Jesus, a person must believe and receive His Words. There are many people who `receive` Christ and yet reject His Words. That is a `corrupt faith`.