Jer 15:1 Then the LORD said to me, “Even if Moses and Samuel stood before Me, My mind would not be favorable toward this people. Cast them out of My sight, and let them go forth.
In the middle of Jeremiah there is a verse in which God laments over how evil Israel had become. To reinforce this, God proclaims that even Moses and Samuel could not convince Him to not destroy the people. Both Moses and Samuel were known in antiquity to have influenced God. This is apparent to any casual reader, just not the Calvinist who claims that God cannot be influenced in any way.
But God does not agree with the Calvinists. In this one verse in Jeremiah, God gives testament to two individual that had powerful sway with God. They could literally convince God to spare wicked people. The Bible described them as doing so.
reality is not optional 
Jeremiah 18 explicitly shows that we can influence God. It also shows that God being called a “potter” doesn’t mean determinism.
“If that nation, against whom I have pronounced, turn from their evil, I will repent of the evil that I thought to do unto them.”