St. Monica May 4

Born in Africa, St. Monica married a pagan, whom she converted by her virtues. Having become a widow she devoted herself to her son, Augustine, whose mind was corrupted by heresy and whose soul was steeped in sin; for about eighteen years she prayed and then saw her sorrow changed into joy.

And when He came nigh to the city, behold a dead man was carried out, the only son of his mother; and she was a widow. — Gospel, St. Luke 7

The Imitation of Christ
Learn now to die to the world, that then thou mayest begin to live with Christ.
St. Monica illustrates the fruits of persevering prayer. The fact that she prayed and suffered for eighteen long years should prove to us how difficult it is to win back for God a soul that has let itself go freely into sin.
If you are praying for some person’s conversion, do not lose courage; pray on, practice little acts of mortification for the same intention; know that you are doing a work most pleasing to God.
He that shall convert one sinner from his evil way, shall save his own soul from death.