The Bahá'í Faith states that religion has the same foundation, and that there is unity of religion. It is one of the core teachings of the Bahá'í Faith, alongside the unity of God, and the unity of humanity. The Bahá'í teachings state that there is but one religion which is progressively revealed by God, through prophets/messengers, to mankind as humanity matures and its capacity to understand also grows. The outward differences in the religions, the Bahá'í writings state, are due to the exigencies of the time and place the religion was revealed.