Amen. One has to ask the question: Does the Holy Spirit lead a man into error and confusion and contradiction?
The answer is a resounding "no."
Some methodologies and practices may vary according to preference (I include infant vs. adult baptism here because both, when accomplished according to a reformed perspective, are not a means of acquiring God's grace but a sign and seal of God's grace.)
But doctrines such as justification by faith alone are intrinsic to a correct understanding of God's grace and the very reason we are saved. We are saved by Christ's righteousness alone according to God's unmerited mercy alone through faith alone in the One who has paid for our all our sins in full, once for all time, as ordained by God from before the foundation of the world.
Not everyone who is elect believes this today. But all who are saved will eventually come to this joyous knowledge and quickened understanding by the "renewing of their minds." Because God may choose a circuitous path for our walk, but when the Holy Spirit takes us by the hand and leads us, there is but one direction home.
I think Baptism is a great case in point. If our practices differ on this it really is not a big deal, if it is not necessary for salvation.