Are Hero Points in Elric?
(I only have Chaosium's Stormbringer, not Mongoose's Elric).
I do have MRQ2 and LEGEND however. Perhaps you can grant Hero Points for acting accordingly to the virtues associated with the deity you have a Pact with, although I'ld limit this to dramatic actions, not everyday virtues and customs. The Hero Points can be used or accumulated as usual, or 'cashed in' as 'Dedicated POW' for purposes of Pacts.This is at the same rate as expending a POW characteristic, gaining an automatic 01% in Pact %.
So in this manner the character can be rewarded for behaving in a manner pleasing to the deity. It's pretty much along the lines of the rules in any case, as I remember that MRQ2/LEGEND has something written about emulating your deity being related to increasing Pact %. Perhaps you can have a loose definition of what emulating your deity is, it may include sacrifices or specific behaviours. I'ld still limit it to the more dramatic ones, and assume the character is behaving in accordance with the deity's virtues in regards to everyday behaviour, or risk suffering Pact % loss.
The more I think of this I think it actually is in the rules, but I don't have my copy to check - if I was at my home PC I could just check my $1 USD pdf of the LEGEND core rules that I picked up at the start of the year...