How far may one deviate from the gospel? Simply speaking, if one’s doctrine interferes with the gospel to the point where it begins to replace it, that line has been crossed. To teach that one must speak in tongues to be saved or that one’s baptism plays a role in salvation is to go too far. May God cause us to adhere to the truth of the Scriptures: faith alone in Christ alone. To add anything to this is to ruin it.
"Have all the gifts of healing? do all speak with tongues? do all interpret?"