Those who fear gods are said to have Theophobia.
This phobia is often the result of an overwhelming suspicion that we do not measure up to the standards of the deity we chose to follow.
Some may have older family members that believed in a faith perspective and then walked away avoiding all future contact or interest in that religious perspective. Their avoidance may have been construed as fear which resulted in the same apprehension in the observer and may later have morphed into the same phobia.
Avoidance will be a primary symptom related to this fear. This phobic personality will avoid houses of worship, religious texts and interaction with others who may believe in the deity. Their fear may be expressed in visible horror or a lashing out at all who state a belief in the deity.
Other symptoms may also include anger, frustration, trembling, elevated heart rate, nausea, feeling as if you are losing your mind, an urge to prove others wrong who believe in the deity, weeping.
This fear can be especially troubling because it deals with a belief system that relies on rewards and punishments both now and in an afterlife.
Therapy coupled with spiritual guidance can be helpful in answering questions about the source of the fear as well as a tool to help clear up any misconceptions about the deity being feared.
Overcoming fear is never an easy answer, but it often requires the help of others in both understanding and acceptance.