Asgar was a devout follower of Ilmater, usually quite serene, and very wise.
Asgar led a small clergy of only six priests, three novices, and four lay worshipers. The House of the Suffering God was a very poor and rundown temple, and the tithes were too few and too small to pay for repairs. Without enough local support, Asgar knew his temple was at risk of being shut down and further that the Zhentarim were infiltrating the town.
For guidance, Asgar relied on dream-visions sent to him by Ilmater. However, the Zhents apparently discovered this and started to magically meddle with what he thought was sent to him by his god. These other visions showed Ilmater turning his back on the House of the Suffering God, but were always shortly followed by mysterious, silver-tongued visitors seeking to purchase the temple, so Asgar disbelieved them. The calm and serene Asgar was so angered and felt so defiled that from then on he'd battle any Zhent agent who threatened him.
Thus, when he saw no other solution to his problems, Asgar went to the Harpers of Berdusk, a town nearby, for help even though he saw them as dangerous meddlers. He asked them to keep Asbravn free of Zhentarim agents and keep his own clergy pure. His hatred of the Zhentarim made him ally with the Harpers, trusting his own secrets to them and healing or otherwise aiding any Harper in need who sought him out.