Dalamar is still within the ability to use his Devotion because he still follows the beliefs the Church sets forth. The others that lost that power were the ones that turned against us, and sought to destroy us. That cannot be denied. Dalamar follows the path of the Church, and seeks to attain Righteousness as much as he can. He may falter along the way, but he does try. For that glimmer of hope we see in him, he is still a part of us in some small way. If just in faith. Were he to turn against us, obviously he would hold no Devotion to the Church's cause or the Gods he once believed in, so therefore would lose that power.
It is up to the Arch-Prelate of the Church to decide whether or not to strip that power from them. There should be no further debate on the subject of Dalamar being stripped of that power until the day he turns his back on those beliefs that give it to him.

Rezzo, Pointer of the Obvious

Penned by my hand on the 1st of Phaestian, in the year 237 AF.