Hi OneWingShark,
Ask them about Jesus’ parable of the Prodigal Son—specifically that the Father declares that his dead son has come back to life. The son made the decision, while dead, and started back to his Father’s house without the father.
I’ve asked them to explain this parable in light of their views, but they have not been able to so far.
If you have been following this discussion, perhaps you missed the explanation of this type of matter. Of course, the son "decides" to come back to the father. Of course we make decisions. That is not actually at issue. The issue at hand is "why?". The issue is, what is driving these decisions? Did the son decide to return completely on his own? Or did God break his heart and cause him to turn back?
If the son was a picture of the beginning of the New Covenant (which, incidentally had not been "inaugurated" until the blood was shed) then the truth of Jer. 31:31ff was in effect. ...I will put My law within them, and on their heart I will write it; and I will be their God, and they shall be My people. And they shall not teach again, each man his neighbor and each man his brother, saying, 'Know the LORD,' for they shall all know me,..."
Paul describes the outworking of this God-initiated rescue as he writes that, "...even when we were dead in our transgressions, (God) made us alive together with Christ (by grace you have been saved), and raised us up with Him,..." Eph. 2:5ff. That is what drove the son home to the father; not some kind of free will choice. It operated exactly the way it did in Lydia (Acts 16:14, "...and the Lord opened her heart to respond to the things spoken by Paul." Sounds like God working...not Lydia having "free will".
Unless you are a universalist, what Jesus says about some being drawn and some not is a very poignant statement. Those who are not...cannot come to Him. This should humble us if we are drawn. Not everyone is granted such grace. Truly,..."no man can come to Me unless the Father draws him,..." John 6:44. If you believe that each man stands with his own destiny in his hands, you believe a gospel described in some Book other than the Bible.
I am surprised no reformed-thinking believer has provided this kind of explanation before. It is the most basic of good theology. Do you feel you have had an answer to your inquiry?
Good point; but there's another parable that can also be used. That of the Talents. If man does not have free will then the master, who represents God, cannot justly throw the last servant into outer darkness precisely because that man had no free will; of course in their world-view all mankind seems to be little more than remote-controlled robots.
Which brings us full circle to the parable of the prodigal son. God constantly/consistently paints Himself as a parent, particularly a father (though there are some references as a mother as well). But what sort of parent would be called good or loving that treated their [normal] child the same way at 40, or 20, or 15, or 10 as the did when he was an infant?
None would... and yet these folks would have us believe that God gives stones instead of bread, and snakes instead of fish, eternally treating His children as as infants, indeed as less than persons.