Praying for the conversion of sinners.
If many of these poor sinners would know that God loves them and wants their salvation, perhaps they would abandon their sinful ways:
Isaias (Isaiah) 1:16 - 18
 Wash yourselves, be clean, take away the evil of your devices from my eyes: cease to do perversely,  Learn to do well: seek judgment, relieve the oppressed, judge for the fatherless, defend the widow.  And then come, and accuse me, saith the Lord: if your sins be as scarlet, they shall be made as white as snow: and if they be red as crimson, they shall be white as wool.