2 Peter 2:15-16 (HCSB)

They have gone astray by abandoning the straight path and have followed the path of Balaam, the son of Bosor, who loved the wages of unrighteousness but received a rebuke for his transgression:A donkey that could not talk spoke with a human voice and restrained the prophet’s irrationality.

     I just read the account of Balaam in Numbers last week.  Here Peter comments about it.  He compares those who have gone astray from the straight path of faith with Balaam who was told not to help Balak, but headed out to do so anyway.  His donkey crushes his foot against a stone wall—the donkey sees the Angel of The Lord, but Balaam does not—and Balaam begins to argue with his donkey, quite without considering the fact that the donkey is speaking!
     The donkey restrains the prophets irrationality.  Humble incident, this.  Balaam is an ambivalent figure in the OT, because he blesses Israel three times—annoying Balak to no end—but then also gets them to intermarry with the Moabites, thus leading the Israelites astray.
     Expositor’s Bible Commentary: “The false teachers have left the biblical way and have gone into Balaam’s error—mercenary greed and sexual impurity.”
     “The wages of unrighteousness” are no comparison to serving and loving the God who bought us back from the edge of death, dear reader, no comparison at all.