I have created a character which bases his existential understanding on that positive energy and negative energy is the fundamental energies in the world, and that the friction between these two creates everything else. His main aim (as a person of true good- NG alignment) is then to eliminate negative energy by using positive energy. This will of course have some unimaginable consequences, but that is not important here. So I am looking for inspiration to create something out of positive energy that is not only healing, but something more, like negative energy is more then harm spells. I know that there is a lot of spells that use positive energy, but they are mostly mixed with fire\sun and such, and I am looking for something pure, the essence...

The focus is the effect of positive energy in the material planes. If you have thought about something similar or know of some spells that is purely positive energy spells please post it here.

Some examples that I have figured out is that a person might infuse him\ her self with positive energy through a ritual (pact). This might perhaps either magnify the other energies a person consists of so that the person grows strong or that positive energy fuels it self with the other energies and then gets stronger before it erupts in a blast which destroys\ dissolves that which is close to the blast.
In short: to use positive energy to strengthen or weaken other energies, either by willing sacrifice or by attacking.
It might also be possible to revive just dead soldiers (material plan beings) into "divine" beings like angels and the like for a short while.

I will be greatfull for most replies because I am trying to create a prestige class and a new form of "magic" which as told is focused on positive energy. ( The reason is that it seems that negative energy has this allready, like necromancy, death and a bunch of classes, while positive energy sort of stands on the side... Why is this? I do not know, or perhaps it is not so)

Greetings from Sunlit...

Greetings, Sunlit! If you're new to the Forge, welcome!

I recently acquired the Eberron campaign setting book, which plays with positive and negative energy in interesting ways. It introduces a kind of undead called Deathless that are good-aligned and animated by positive energy instead of negative energy. It also includes a Deathless domain for clerics. I won't recommend borrowing these ideas wholesale (such as designing a prestige class that turns you into a "Deathless lich" or something), but it may give you something to think about.

As far as offensive positive energy spells go, you may want to design magical effects that mimic the effects of spending too much time on the Positive Energy Plane (as outlined in the DMG.) If memory serves, it causes characters to keep gaining more and more temporary hit points until their bodies can't hold any more and they explode in a burst of light. The same spell could be beneficial or deadly, depending on how long the effect is sustained.

You could also design a prestige class that can rebuke/command living creatures the way that clerics who channel negative energy can rebuke/command undead.
Anyway, I hope this helps.

Hi Sunlit (is there a real world name we may call you by?)

Also, welcome to the Forge! 

As far as your questions- it sounds mostly like what you want to do is make a prestige class that does things that other classes do, except the focus being on clerical type magic.  First, I'd recommend looking at The Complete Divine supplement, which focuses on that- perhaps at least skimming it at a game store or Barnes & Nobles to see if any of the ideas in there fit what you need.  That aside, the other thing to do would be to simply port over other abilities into the Prestige Class you're thinking of.

For example- make a clone spell of "Animate Dead", and alter it where you see fit.  (for example, "Must also use a Turn Undead attempt and spell lasts 1/round per caster level" or whatever fits your bill).

For the purposes of balance, you may wish to make any ability or power that is a "clone" of another class' ability or power a little weaker or at a higher level to acquire. 

Other than that, my best recommendation to you is to check out the forum boards over at Wizards, if you haven't already, and perhaps scan through some of the free online resources such as www.d20srd.org to check out online OGL material for reference.  Your request for help on a single prestige class might be a little too narrow and focused to be able to get much help here, but the hardcore system monkeys on the Wizards boards will definitely be able to give you in-depth D20 help.

Chris