Blessing of Light

Blessing of Light places a Blessing on a friendly target which increases the effects of Holy Light (Classic) and Flash of Light spells on the target. A player may only have one Blessing per Paladin at any one time.

Paladins also have Greater Blessings, which includes a Greater Blessing of Light which can be learned (purchased) from the Class Trainer. Each Greater Blessing affects all players of the targeted class within your party or raid and lasts for 30 minutes (as of patch 2.2).

Each Greater Blessing you cast requires the reagent Symbol of Kings which can be bought at any reagent vendor.

A great use for this Blessing is to put it on your tank. Your healing spells will be more efficient. However, it should be noted that it does not improve the healing of other non-paladin healers.

While Blessing of Light claims to add "up to" a certain amount to specific healing spells, in practice it actually adds the full amount to those spells. That is to say, it does not behave like spell power gear (which uses similar language), which adds an amount that depends on the casting time of the spell. If you compare Blessing of Light (Rank 4) with +heal gear, it's the equivalent of +440.4 for Flash of Light, and +777.7 for Holy Light.