So you don't consider Presbyterians to even be Christians?
Westminster Confession of Faith: Chapter 28. V. " V. Although it be a great sin to contemn or neglect this ordinance, yet grace and salvation are not so inseparably annexed unto it, as that no person can be regenerated or saved without it; or, that all that are baptized are undoubtedly regenerated."
Amen. Nothing saves but the shed blood of Christ for the sins of His flock.
Baptism brings us into Christ. It follows that those who are outside of Christ cannot be in the Church. It is an individual state and not of the whole assembly.