Whether predestination is certain?

❌ Objection 1 : It seems that predestination is not certain. Because on the words "Hold fast that which thou hast, that no one take thy crown," (Rev 3:11), Augustine says (De Corr. et Grat. 15): "Another will not receive, unless this one were to lose it." Hence the crown which is the effect of predestination can be both acquired and lost. Therefore predestination cannot be certain.

❌ Objection 2 : Further, granted what is possible, nothing impossible follows. But it is possible that one predestined---e.g. Peter---may sin and then be killed. But if this were so, it would follow that the effect of predestination would be thwarted. This then, is not impossible. Therefore predestination is not certain.

❌ Objection 3 : Further, whatever God could do in the past, He can do now. But He could have not predestined whom He hath predestined. Therefore now He is able not to predestine him. Therefore predestination is not certain.