Well, let’s not go overboard. We know, positively know many things, but that is neitier here, nor there.
This whole exchange was triggered by your post that you may buy an ice-cream if your niece asked for it, but would not buy if she did not - and you added the proviso that you “positively know” that she will ask and that the ice-cream parlor will be there, and it will be opened, and the weather will be nice to take a stroll… and many other things. We can disregard this latter part, and concentrate on the first: “if she asks, you will buy, if she does not, you will not buy”.
Indeed it was my mistake that I neglected to reflect on this part, which is the important one. I apologize for concentrating on the other part.
What you say is perfectly true as far as your example goes. You decided that you will make a conditional action, based upon the request - which is fine for us, human beings. This cannot be applied to God. God’s actions cannot be contingent upon what we ask or do not ask. That would make God’s action contingent upon us, and God is not supposed to be contingent at all. God is “simple”, has no parts, his knowledge and his actions are an inseparable part of his “essence”.
Therefore, our supplication is irrelevant. Whether we ask for something or not, God will do whatever he does. We cannot “nudge” God by a supplicative prayer, therefore supplicative prayers are futile - no matter what the Bible says.