See, divine abilities are usually either absolute or work by percentile rolls. If you can stand rolling percentile dice in the pseudo-d20 system, it's eminently portable. Take, for example, the abilities of "All Gods":
All gods, from Lesser to Demi-, have the powers described this section. Although these are powerful abilities, they are taken for granted by the deities in this book.
Immortality: All gods are immortal. The only way for a god to die is to be destroyed by a god of higher statue in magical or physical combat. Otherwise, any god that suffers an attack that should destroy it simply disperses, then reassembles later (roll percentile dice to determine number of days). So, for example, a god which is seemingly torn apart by a powerful artifact would simply be dispersed, only to reassemble later.
Teleport: All gods possess the innate ability to instantly teleport to any point on the same plane. They can do this at will and without any chance of error.
Initiative: When dealing with mortals, all gods automatically receive the initiative. Of course, they can choose to simply wait and see what the mortals opt to do, but they may always act first if they desire.
Comprehend Languages: All gods understand and can speak any language. It is assumed that this includes written and spoken languages as well as other, more unusual, forms of communication like the light and color based dialect of the will o’wisp.
Magic Use: All gods may use any spell of any level. This includes the spells of priests or wizards and does not require the use of spell books, prayers, or material, verbal, and somatic components. In short, invoking such powers requires the slightest act of will on the part of these incredible beings.
Okay, the last part references spells, but you can just port it right over (Wizards and Clerics still use "spells") or say that gods now may use any power available to a player character. Of course, if you want to make gods manageable in combat, you may want to strike that part and give them powers. But teleporting at will? Always winning initiative? Speaking any language? That's just fine.
There's more, of course. The book goes on to stat up generic Greater, Immediate and Lesser Gods, Demigods and Heroes. I'll just quote the Greater God stats:
In addition to the abilities above, Greater gods can do practically anything. In most cases, they are the gods who created the rest of the pantheon. Some of their additional abilities include.
Shapeshifting: Greater gods can transform themselves into any object, animate or inanimate, of any size. In some cases, beings of this stature have been known to assume planetary proportions.
Magic Resistance: Greater gods are 100% resistant to mortal magics, 75% resistant to the magic of gods of lesser ranks, and 50% resistant to the spells of other greater gods.
Saving Throws: All greater gods are assumed to automatically make all saving throws required of them. This is a reflection of their great abilities, mental powers, and physical stamina .
Planar Travel: Just as they can teleport across space without error, so too can they travel between the various planes of existence at will. As mentioned earlier, however, even these powerful beings cannot enter the true Prime Material Plane.
Sensing Ability: These beings are truly omniscient. That is, they know what is happening everywhere at all times. In many cases, they can accurately predict the precise actions of mortals and other gods based on their vast knowledge.
Creation: Greater Gods can create any object, animate or inanimate, they can think of. This process is draining, however, since they are converting their own energy stores into physical objects. Therefore, the god must rest for one turn per ton of mass he or she wishes to manifest. Thus, the creation of a 10 ton stone statue would require that the god rest for 10 turns (100 minutes) afterward.
Life and Death: Greater gods can kill any living mortal creature with but a thought. Likewise, they can bestow life upon any slain mortal being anywhere. Of course, another greater god can reverse effect immediately if so desired.
Communication: Greater gods can speak directly and secretly to any being across any void and through any physical or mystical barrier. This power transcends the bounds of space and planes, but not (as a rule) time.
Multi-tasks: Greater gods can perform any number of tasks at once. Of course, natural limitations based on their current physical form may apply, but there is never a penalty on their actions due to complexity.
Avatars: Greater gods can employ up to ten avatars at a time, moving them between planes at will. If one is destroyed, it requires one day to make another.
Granted Abilities: A greater god can grant any power or spell of any level to his or her priests. It is through this ability that deities give priests and paladins their magical powers.
Magic Resistance is an interesting one. Any magic used by a PC just fizzles against a greater god. And if Odin and Zeus (indeed Greater Gods in the sourcebook) duke it out, their attack spells work half the time. In a D&D4 conversion, the question is whether to port this straight over (use the percentages for any power including martial ones) or use it in addition to level appropriate defenses (first you roll to attack, then the god gets to use it's magic resistance). I feel that using the percentages might give the Gods a special feel - even the system is different when encountering them!
For comparision, even a demigod is 70% resistant to "magic" used by a mortal. That's still "just" a 30% hit rate compared to the approx. 50% hit rate a PC could expect against level-appropriate monsters.
And then there's saving throws, which mean different things in AD&D and 4E. (For those who don't know, AD&D's saving throws represent 4Es defenses, while 4Es saving throws are a normally straight d20 roll to end a magic effect. If you roll 10 or more, it stops.) Still, I'd use this as written. Greater Gods end all "save ends" effects at the end of their turn.
Then the book gets into crunch, including how to become a Demigod (already covered in 4E). Over and out for me.
In 4E, deitites are a lot simpler. Their non-combat abilities aren't statted up, true, but their combat specialty also boils down to "Normally, a deity discorporates and retreats for a while when brought to half HP. By performing a specific quest, the PC:s can disable this ability." Works for me, but Legends & Lore is just so interesting.