How can you “exhaust” a sovereign, predestining God?
By disobeying Him. The Bible teaches two truths that we like to put at odds with one another. First, God is sovereign (in control of all things) and second, our obedience matters. Continual disobedience on our part will eventually exhaust God's patience and will result in judgment. Thankfully, God is being patient with us, giving us all time to repent, turn to Christ in faith, and follow Him in obedience.
Who said the quote you referenced: “How dare we find entertaining something Christ had to die for?”