There is no reason in man for predestination. God acts both the willing and the fulfilling. But Augustine was not a determinist in the technical psychological sense. Predestination does not exclude man’s will. The psychological will of man is preserved and distinguished from external forces, or from compulsory elements in man. But the direction of the will towards Hod is dependent on God’s predestination and this predestination cannot be explored.
Grace is given to everybody who becomes a Christian. The forgiveness of sins, which is first given to him happens in baptism and is received by faith. In this Augustine continues the general tradition. But beyond this, forgiving is a real participation in the ultimate good. This ultimate good has appeared in Jesus as the Christ, without which neither good thinking nor good acting nor loving is possible. Now he describes this side of grace as the inspiration of the good will, or he also calls it the inspiration of love, namely first of all the love towards God. “The Spirit helps,” he says, “by inspiring in the place of bad concupiscence, good concupiscence, that is, diffusing carinas (agape) within our hearts.” Justification therefore is inspiration of love. Faith is the means to get it. But faith at that time already had the deteriorized sense which today makes Christian preaching about faith almost impossible, namely faith as tile acceptance of doctrines which are unbelievable. So Augustine distinguishes between two forms of faith. He calls faith crater deo aut christo, namely believing “to” God or “to” Christ, namely, accepting their words and commands; and the other is believing “into” God and “into” Christ. The first is an intellectual acknowledgment, without hope and love. The second is a personal communion which is created by grace, or by the Holy Spirit, or by love – these words are all the same. This alone is the faith which justifies, because it makes him who is justified just.
Those who are predestined are of course naturally able to fall away again, so they get something else: they get the gift of perseverance, of sticking to what they have received, the gift of not losing the grace. All this, the whole process I have just described, does not depend on any merit, not even on the merit of non-resistance against grace, since grace, as Augustine emphasizes, is irresistible; when it comes to you, you cannot resist it, and you cannot get it if it doesn’t come to you.