Why do Religions use light?

Light is symbolic of the Light of Christ or the light of knowldge and truth. It is the opposite of darkness. Christ is the Light while Satan is nothing but darkness to light and truth. One may hear the saying "I have seen the light" meaning that one has a testimony of Christ and the truthfulness of the gospel. Coming into the Light is coming from ignorance to knowledge of the truth of all things. When one come to the Light of Christ one needs never fear the darkness again, for light banishes all darkness.