St. Paul expressly ascribes the salvation of man to grace when he says: “... with fear and trembling work out your salvation; for it is God who worketh in you, both to will and to accomplish.”(337)
The Tridentine Council, as we have seen, designates the four salutary acts of faith, hope, love, and penitence as a preparation for justification. Now St. Paul teaches: “The God of hope fill you with all joy and peace in believing, that you may abound in hope and in the power of the Holy Ghost;”(338) and St. John: “Charity is of God.”(339)
b) The argument from Tradition is chiefly based on St. Augustine, who in his two treatises against the Semipelagians, and likewise in his earlier writings, inculcates the necessity of grace for all stages on the way to salvation.
Thus he writes in his _Enchiridion_: “Surely, if no Christian will dare to say this: It is not of God that showeth mercy, but of man that willeth, lest he should openly contradict the Apostle, it follows that the true interpretation of the saying (Rom. IX, 16): ‘It is not of him that willeth, nor of him that runneth, but of God that showeth mercy,’ is that the whole work belongs to God, who both prepares the good will that is to be helped, and assists it when it is prepared. For the good will of man precedes many of God’s gifts, but not all; and it must itself be included among those which it does not precede. We read in Holy Scripture, both ‘God’s mercy shall prevent me’ (Ps. LVIII, 11), and ‘Thy mercy will follow me’ (Ps. XXII, 6). It precedes the unwilling to make him willing; it follows the willing to render his will effectual. Why are we taught to pray for our enemies, who are plainly unwilling to lead a holy life, unless it be that God may work willingness in them? And why are we admonished to ask that we may receive, unless it be that He who has created in us the wish, may Himself satisfy the same? We pray, then, for our enemies, that the mercy of God may precede them, as it has preceded us; we pray for ourselves, that His mercy may follow us.”(340)
That grace accompanies us uninterruptedly on the way to Heaven is also the teaching of St. Jerome: “To will and to run is my own act; but without the constant aid of God, even my own act will not be mine; for the Apostle says (Phil. II, 13): ‘It is God who worketh in you, both to will and to accomplish.’... It is not sufficient for me that He gave it once, unless He gives it always.”(341)