A man might flatter, or bribe, or coax a tyrant; but there is no refuge from the love of God; that love will, for very love, insist upon the uttermost farthing.
If you were never close to your father, or you had a weak father, you will probably find the following statement about God difficult to understand.
"His nature is always to forgive, and just because he forgives, he punishes."
Here is the statement in its fuller context.
"To regard any suffering with satisfaction, save it be sympathetically with its curative quality, comes of evil, is inhuman because undivine, is a thing God is incapable of. His nature is always to forgive, and just because he forgives, he punishes. Because God is so altogether alien to wrong, because it is to him a heart-pain and trouble that one of his little ones should do the evil thing, there is, I believe, no extreme of suffering to which, for the sake of destroying the evil thing in them, he would not subject them. A man might flatter, or bribe, or coax a tyrant; but there is no refuge from the love of God; that love will, for very love, insist upon the uttermost farthing." (George MacDonald, Justice (full sermon)).*
"If God has forgiven everyone, and he punishes those he forgives, does this mean he will punish everyone?"
No. Some children admit they're sorry and begin to do what is right. Some choose a much harder path. It is very hard for them because no one can resist God's will forever. In the end his will will be done.
* Those who are C.S. Lewis fans might be interested to know that George MacDonald was Lewis' favourite author. See here.