If God extends His grace and call to all men equally, then why do some men come while others resist, except that there be something within the one that is not within the other. If that is the case, then the one who comes has reason to boast over the one who continues in his rebellion. God’s saving grace is reduced to a shallow pool that covers all men slightly while man’s will contains the real power to ebb and flow toward or against the Almighty’s outstretched hand.
But if man’s will is the stagnant pool unable to extend itself beyond it’s own sinful desires, then where is the boasting except in the Triune God, when His tidal wave of grace washes over that little cesspool of our heart swallowing it up into the endless ocean depths of Christ’s glory and kingdom. The stagnant water is not then swept along by this powerful force from the outside, but begins to take on a saltiness and becomes a unified part of this flowing tide as it moves along. These brackish waters of life between two worlds are taking us ever onward until the glory of the Lord consumes all things as the water cover the seas.
“Man is not borne along without any motion of the heart, as if by an outside force; rather, he is so affected within that he obeys from the heart.” – John Calvin, summarizing St. Augustine.