Is reincarnation a viable Christian option, or is it antithetical to the Revelation of God in Jesus Christ?
To begin with, Scripture itself does not exhaust Truth, because Jesus Christ IS the Truth (John 14:16). If we want to understand the true nature of God, and therefore Life, we must look to Jesus (1 John 5:20). We are called to follow the guidance of the Lord's Spirit as it endeavors to lead us "into all the Truth" (John 16:13).
When we cast our eyes upon Jesus, we see that God is Love (1 John 4:16). Christ Love is True God and True Life (1 John 5:20). Reincarnation need only prove consistent with the image of God that we see in the person of Jesus Christ in order to be seen as a viable expression of our Faith.
True Heresy, therefore, is not so much an extra-canonical belief as it is the refusal to allow the Spirit of Christ to lead us into the fullness of Truth, into new understandings of reality entirely consistent with the Revelation of Jesus Christ that God is Love!
Heresy is the act of closing ourselves off from the shepherding guidance of the Spirit of Truth.
It is a false, antichrist presupposition that the Holy Spirit has nothing more of consequence to say to us. Paul warns us of the very grave dangers in quenching the Spirit of Truth (1 Thess. 5:19).