Balaam is a prophet living in the region of Pethor, and he is synonymous with a fallen prophet.
Num 22:5He sent messengers to Pethor, which is by the River, in the land of the children of his people, to call Balaam the son of Beor, saying, “Behold, a people has come out of Egypt. They cover the face of the earth and are dwelling opposite me.
Balak, the king of Moab, knowing that he could not defeat the Israelites who had come out of Egypt in war, invited Balaam to curse them.
Initially, Balaam refused, but blinded by the great wealth offered by Balak, he rode his donkey towards Balak. On the way, he received a warning through the donkey's mouth and also from an angel, but unable to overcome his greed, he proceeded to curse them.
Num 22:28Then the Lord opened the mouth of the donkey, and she said to Balaam, “What have I done to you, that you have struck me these three times?”Num 22:29And Balaam said to the donkey, “Because you have made a fool of me. I wish there were a sword in my hand, for then I would kill you.”Num 22:30And the donkey said to Balaam, “Am I not your donkey, on which you have ridden all your life long to this day? Have I ever been accustomed to do so to you?” And he said, “No.”Num 22:31Then the Lord opened the eyes of Balaam, and he saw the angel of the Lord standing in the way, with his drawn sword in his hand. And he bowed down and fell on his face.Num 22:32And the angel of the Lord said to him, “Why have you struck your donkey these three times? Behold, I have come out to oppose you, because your way is perverse before me.Num 22:33The donkey saw me and turned aside before me these three times. If she had not turned aside from me, surely just now I would have killed you and let her live.”
However, when he tried to curse, God controlled his mouth and made him bless instead of curse.
Nevertheless, Balaam did not give up. He told Balak, the king of Moab, that if the Israelites were led astray to eat food sacrificed to idols and commit sexual immorality, they would incur God's wrath, thus causing trouble for the people.
Rev 2:14But I have a few things against you: you have some there who hold the teaching of Balaam, who taught Balaam to put a stumbling block before the sons of Israel, so that they might eat food sacrificed to idols and practice sexual immorality.