As long as people embrace contradictory premises that abandon logic it is impossible for them to arrive at the truth. Consequently, in theology it can be exasperating to show a person the contradiction of their Calvinism, because they embrace the contradiction. You are only pointing out what they already admit to. In fact, they do not even believe their contradiction is a real contradiction, but only a ‘seeming’ one. This is why a great division in Christian theology has continued to exist for centuries despite proponents from both sides appealing to the Bible….
My own personal experience, years ago, in embracing the doublethink of Calvinism was a frustrating one. I would liken it to riding a rocking horse. As a rider, I would throw my weight forward toward my belief in the absolute sovereignty of God until I could go no further, whereupon I would recoil backwards toward my belief in human freedom. Thus I would go back and forth in seesaw motion, lest on the one hand I find myself accusing God of insufficient sovereignty, or on the other hand find myself accusing God of authoring sin. All the while, there remained an illusion of movement towards truth, when in fact there was no real movement at all. Calvinist riders still ride out this scenario. This is why, among the Calvinistic writings of Van Til, Sproul, Boettner, etc., there are no unqualified statements about the absolute sovereignty of God or the free will of man. If one reads long enough, all forthright statements about them are eventually withdrawn by qualifying each statement with its exact opposite thought. This explains why every book and article advocating the absolute sovereignty of God ends with its terms unconcluded…..
The tension of qualifying coils always limits the movement of the horse from going too far in either direction, and because the horse cannot stop to rest at either of its polar positions it must stop in the middle. Thus, the Calvinist continues his ride ad infinitum until he has exhausted his energy in trying to ride out the contradiction. Finally, he declares the polar positions of the horse to be reconciled by tension, brings the horse to its synthesized (dialectical) center, and gets off. These long rides of to and fro motion is why Calvinistic treatises on the subject of predestination tend to be so repetitive. With the problem of evil, then, readers go back and forth while Boettner tells them that “we have removed blame from God” even though four sentences earlier he said that “God is ultimately responsible for it”!
From: Divine Sovereignty