Can Prayer Change What God Almightiest Has Already Decided?

Others say, "Prayer does not change GOD. Prayer brings us into agreement with HIS will."

But what does the scripture actually reveal? Did Abraham's prayer change GOD's decision concerning Sodom? Did Moses change GOD's mind when he interceded for Israel? Did Hezekiah's prayer alter what had already been spoken concerning his death?

Did Jonah's preaching cause Nineveh to experience a different outcome? And if GOD ALMIGHTIEST is omniscient, knowing the end from the beginning, what does it actually mean when scripture speaks of GOD "repenting," "relenting," or changing a declared course of action?

There is another question that goes even deeper: if GOD has already determined the outcome, was the prayer itself already part of HIS divine purpose?

And what about CHRIST JESUS? When HE prayed in Gethsemane, "Not MY will, but THINE, be done," was HE attempting to change the Father's decision, or was HE submitting to the will that had already been established? So let us settle this properly: does prayer change GOD'S mind, or does prayer accomplish what GOD has already purposed through the prayers of HIS people?

No assumptions. No denominational arguments. No emotional conclusions. Bring the SCRIPTURE.