Can prayer change God's perfect plan?

[WinterHold]

Personally, I believe prayers are answered with either a yes or a no.

Maybe for Islamic God but your line doesn't hold very well with Christian god because he made the promise found in the Bible: "And all things, whatsoever ye shall ask in prayer, believing, ye shall receive" (Matthew 21:22). Nor does it fit well with the tears and pleadings of all those mothers holding near-dead babies in their arms right now at this very moment. A god who ignores those prayers has no business answering any others.

God is one; many Christians refer to him as the father. That's their own business; own belief; own book. They hold responsibility for their faith,
I wouldn't trust the whole bible though; it does contain some right things, but also the wishes and thoughts of the writers. What if I pray that Satan should die? more cunningly: what if I shoot an innocent person while praying I go to heaven?
Maybe because of verses like these; the crusades took place, and thousands of innocents were butchered.

But we are talking about supposedly omnipotent God? Aren't we? Why would a god allow father to use his free will to do evil to son? If this god is powerful and good, and if son is righteous in his eyes, surely he can and is inclined to protect him?

Imagine this: Among humans, a parent who can protect one child from the evils of another but does not do so is a bad parent; how less so a god?

Because there's an afterlife; we weren't created for this life.
It's all a test, an brief examination before the hour.
We were in paradise; humanity showed an inclination to believing and following Satan over God; so God sent both Satan and humanity to earth; bashing each other until the hour.
Satan's fate is well known, but for every human there's a fight to battle through. God knows who will be where, but how is it fair if we didn't live it to be real?