Although the permanent divine power and righteous might is an interesting idea, it could get pretty complicated, what with a dispel magic and all that. Perhaps we should give them something like:
Unholy Power (Su): A composite mummy gains its Charisma bonus to all attack rolls and grapple checks.
Well, part of my concept was Might of the Gods couldn't be dispelled, the only way to suppress it was with anti-magic or by facing the mummy on ground consecrated to an "enemy god". As for the complexity, it's really only a few stat changes, no different from having a buff spell removed.
Perhaps the following rewrite would make it clearer:
Might of the Gods (Su): The god in whose image a composite mummy is crafted grants the mummy supernatural size and strength. This gives the Mummy a Base Attack Bonus equal to its Undead Hit Dice, a +6 unholy bonus to Strength, a +2 size bonus to natural armour, a +2 unholy bonus to natural armour, +1 hit points per Hit Dice, and increases its size by one step (to Large). All of these bonuses are included in its statistics above.
Might of the Gods cannot be dispelled or broken by any mortal magic, although its effects are temporarily suppressed while the composite mummy is within an anti-magic effect or an area consecrated to a god inimical to the mummy's divine patron, via a hallow spell or similar effect. A standard crocodile composite mummy without Might of the Gods has the following changes to its statistics:
(Medium Undead; AC 21 (+1 Dex, +10 natural) touch 11, flat-footed 21; BAB/Grapple +8/+15; Attack Claw +15 melee (1d6+7 plus mummy rot); Full Attack 2 claws +15 melee (1d6+7 plus mummy rot) and bite +10 melee (1d8+3 plus mummy rot); Space/Reach 5ft./5ft.; Abilities Str 24, Dex 13, Con —, Int 12, Wis 14, Cha 15; Skills Swim +?)
A composite mummy's patron god can suspend its gift whenever it wishes to punish its creature for some misdeed or blasphemy (effects as above). The god can also withdraw the Might of the Gods quality from a composite mummy that has entirely lost its divine favour, which immediately destroys the mummy.
Still, if the rest of you prefer Unholy Power I'm fine with that.
I'll just stat out an alternative version, as usual.
