In terms of the grace involved in salvation there is only one grace. The same grace which saves one man will damn another. The grace that saves the man who receives it will condemn the man who rejects it. It would appear to be the same grace.
Then there is but one grace. That one grace is doled out in equal amounts to all men and all men have but to accept (receive, comprehend, acknowledge) that grace. This is the essence of salvation?
Seems reasonable. But I still don't see the equity. From my perspective (a simple human), it doesn't appear that all men are given equal opportunity.
Some people are born to loving, Christian parents who expose them to God's love on a regular basis. Then there are people brought up into horrific conditions from birth to death who never (or rarely) hear God's message of salvation.
It seems that there are environmental factors that will greatly affect our choices. Does God control any of those factors? Can a man be blamed if he never chooses God when he rarely sees evidence of God's love in his life? Certainly some people are given more opportunity than others - is this part of God's "free" choice?
Common grace is the grace of God that comes to all of us. We're told that God sends rain on the just and unjust alike.
In my opinion, common grace is a variety of prevenient grace which is grace that comes before salvation. Another variety of prevenient grace is "enlightening" grace which enables a man to clearly see the choice he must make to believe in Christ.
Are you just making this up as you go along? I can't believe you said that!