
Augustine tells us that in his 16th year "out of muddy concupiscence of the flesh, and bubbling of youth, midsts fumed up which beclouded and overcast my heart, that I could not discern the brightness of love from the fog of lustfulness." (Conf. 2.2.2) Monica with great anxiety warned him "'not to commit fornication; but especially never to defile another's wife.'" (Conf.2.3.7)
Augustine studied in Carthage from age 17 to 19. While there he had relations with a woman who bore him a son Adeodatus (God-given). He began to believe the teachings Manichean, that is, he believed that there was a God of good and a God of evil and that mankind was caught up in this struggle. The Manicheans believed to be on the side of the good spirit for which they would be rewarded. Meantime, since man was compelled to do evil by evil spirit, he was not responsible for his actions.
When he returned home from Carthage, he began to vent his beliefs and Monica threw him out of the house, but due to a dream she had, she changed her mind and allowed him to return home. Monica was sad and cried for many years. One day she went to see a holy bishop in order to beg him to speak to her son. He refused saying that Augustine was not ready to change. As she departed the bishop said to her, "'Go thy ways, and God will bless thee, for it is not possible that the son of these tears should perish". (Conf. 3.12.21)