Righteous Fire drains life faster when i move

I'm a new player and have a lvl 47 fire inquisitor (trying to copy phox build as much as i can). So far my base fire resistance is 76% and base life regen is 162 per sec. Max life is 1410 and ES 121. With Purity of Elements and Vitality turned on I actually heal, but if i am moving, my Hp starts to rapidly drain. I can't figure out why.

Maybe because you are no longer on concecrated ground?
if you've the Sanctuary skill from Inquisitor