The Bless spell raises the morale of friendly creatures, giving them a +1 bonus on saves vs. fear effects and a +1 bonus on attack rolls.
Upon uttering the Bless spell, the caster raises the morale of friendly creatures by +1. Furthermore, it raises their attack and damage rolls by +1. The caster determines at what range (up to 40 ft.) the spell will be cast. At the instant the spell is completed, it affects all creatures in a 30-ft. radius centered on the point selected by the caster (thus, affected creatures leaving the area are still subject to the spell's effects; those entering the area after the casting is completed are not).