And as we teach, moreover, that “wisdom will not enter into the soul of a base man, nor dwell in a body that is involved in sin,” we say, Whoever has clean hands, and therefore lifts up holy hands to God, and by reason of being occupied with elevated and heavenly things, can say, “The lifting up of my hands is as the evening sacrifice,” let him come to us; and whoever has a wise tongue through meditating on the law of the Lord day and night, and by “reason of habit has his senses exercised to discern between good and evil,” let him have no reluctance in coming to the strong and rational sustenance which is adapted to those who are athletes in piety and every virtue.
And since the grace of God is with all those who love with a pure affection the teacher of the doctrines of immortality, whoever is pure not only from all defilement, but from what are regarded as lesser transgressions, let him be boldly initiated in the mysteries of Jesus, which properly are made known only to the holy and the pure. The initiated of Celsus accordingly says, “Let him whose soul is conscious of no evil come.” But he who acts as initiator, according to the precepts of Jesus, will say to those who have been purified in heart, “He whose soul has, for a long time, been conscious of no evil, and especially since he yielded himself to the healing of the word, let such an one hear the doctrines which were spoken in private by Jesus to His genuine disciples.”
Therefore in the comparison which he institutes between the procedure of the initiators into the Grecian mysteries, and the teachers of the doctrine of Jesus, he does not know the difference between inviting the wicked to be healed, and initiating those already purified into the sacred mysteries!
Source: Against Celsus (New Advent)