CONVERSION. - A term derived from the Latin convertere (to turn, to turn back), which in theological language generally means the return of the erring soul to God, and therefore the passage from the state of sin
(aversio a Deo) to the state of grace (conversio ad Deum). In this sense conversion coincides with justification (v.), which also occurs in a Christian believer who is a sinner, and who regains Grace.
More properly, conversion is to be understood as the first conquest of faith and consequently of sanctification, or else as the reconquest of lost faith. It is therefore a passage from atheism or even from false religions to the true faith, which is that of Christ and of his Church. It is also a passage of dissident Christians (schismatics, Protestants, apostates, heretics) to Catholicism, which is in the Roman Church. In all these categories, unbelief or the lack of true faith is frequently in itself a fault (except in cases of invincible ignorance or psychic anomaly), and in any case exposes man to a graver danger of sin, keeping him outside integral Christianity, in which supernatural helps abound for elevating and strengthening the spirit weakened by original sin. Therefore, upon all those who are outside the Church there objectively rests the duty to be converted; subjectively, however, this duty is not imposed except to the extent of one's awareness of one's own responsibilities before the problem of faith and salvation. Whoever has at least the doubt of being off the road must seek, must pray in order to find.
But conversion, according to Catholic doctrine, is not the fruit of human efforts; it is always of a supernatural character and therefore requires a divine intervention. The Council of Trent, sess. VI, cc. 5-6-7 (Denz-U, n. 797 ff.), describes in detail the conversion of the adult from the state of sin to the state of sanctification. First of all there is a preparation, which is the fruit of a cooperation between God who enlightens and moves and man who docilely consents, while he could resist (c. 5). In particular, conversion begins with an act of faith, which is the adherence of the intellect to the truth revealed by God, under the impulse of an exciting Grace. Then the soul thus enlightened recognizes itself as sinful and, trusting in divine mercy and in the merits of Christ, has a movement of hatred against sin and of love toward God (c. 6). This preparation is followed by justification, which consists in the remission of sins and in sanctification or interior renewal through the infusion of Grace, which is inscribed in the soul as a formal principle of holiness (c. 7).
The Council did not intend thereby to determine the chronological order of the phases of conversion, but only to indicate its principal components, which act slowly or instantaneously, in different ways, according to the mysterious designs of God and according to the delicate conditions of human psychology. The Tridentine doctrine is anticipated by St. Thomas, who gathers and synthesizes the voices of divine tradition in Sum. Theol., 1a-2ae, qq. 112-13, where he carefully traces the itinerary of conversion from the preparation under the influence of actual Grace up to the infusion of sanctifying Grace, which coincides with the remission of sin. St. Thomas holds firm to two principles regarding preparation: God's initiative in the work of conversion and the subordinate cooperation of human free will. Although he did not have full knowledge of Semipelagianism (v.), already condemned by the Second Council of Orange (529), the holy Doctor refutes its fundamental error, which consisted in attributing to man himself the beginning of his faith and therefore of his conversion. St. Thomas, following in the footsteps of St. Augustine, explains the famous aphorism "Facienti quod in se est Deus non denegat gratiam," in the sense that God stimulates man (with prevenient Grace) to prepare himself for sanctifying Grace. And God calls and stimulates all.
The experiences of the great converts substantially confirm what the Church teaches. Even amid the variety of itineraries, the supernatural character of the movement of the spirit toward God is constantly evident, and the decisive moment of conversion is always an intuition, a ray of truly intellectual faith, from which the new orientation and the new life begin. Thus the traditional expression is justified: Fides initium salutis (v. FAITH; JUSTIFICATION).