One of the main problems with the anti-Calvinist/pro-free will argument, as I see it, is that every unsaved person is a slave to sin, the flesh, and the devil (Rom 6:17, 20; 7:5, 18, 25; 8:8; 2 Cor 4:4; etc.). They prefer the darkness to the light, and evil over good (John 3:19-20); "no one understands; no one seeks for God. All have turned aside" (Rom 3:11-12, ESV). It seems that absolutely no one can choose salvation, in the least because they simply don't want to.
As such, in order for anyone to "choose" salvation, God must first do a work upon the heart by the Holy Spirit. And, yet, we know that most people will not be saved, including many who hear the gospel. So, it strongly appears then, that God, according to the non-Calvinist, is choosing in real-time who gets saved and who doesn't. How is that ultimately any different than if he chose those who would be saved before the beginning of the world?
As such, in order for anyone to "choose" salvation, God must first do a work upon the heart by the Holy Spirit. And, yet, we know that most people will not be saved, including many who hear the gospel. So, it strongly appears then, that God, according to the non-Calvinist, is choosing in real-time who gets saved and who doesn't. How is that ultimately any different than if he chose those who would be saved before the beginning of the world?