Fire Blessing, grants the Paladin a fire sword, which can leave burns on the enemy, and it grants the paladin +175% fire resistance.
The Paladin is the elite unit of the Humans, being heavily armored and dealing a lot of damage. However, he needs quite a lot of resources and requires three buildings, making him an expensive unit. With the Fire Blessing, he deals much more damage, because of the Fireburst his sword gives. The Fire Blessing also provides excellent resistance against races that use Fire Magic, like Orcs.
The knights of the Orders of Dawn, the Iron Falcon or Tiaras have always been steady companions of the Army of Light. In among the realm they combine the mobility of mounted crossbowmen with heavy armor and an un-excelled sword arm. Their faith does not only give them power, but also the ability to effect divine magic against the Undead, which makes them particularly effective against these enemies.