Belonging to a religion does not prove you have faith. For it is your behaviour which alone proves faith.
True faith is sustained by your love, your intelligence, and your willpower – qualities that must be shown through behaviour.
To believe in God is to feel you are a son or daughter of God, and to strive to live in accordance with this filiation. A child of God knows not only that they are heir to the qualities and powers of their heavenly Father and Mother, but that they must do everything possible to develop them and thus become master of their destiny.
Every action that is not inspired by true wisdom and love produces toxic matter in human beings and prevents the manifestation of their divinity. Those who know that God is their Father have only to clear and purify the space between this Father and themselves.
And then, yes, they can say they have faith.