Divine grace
The Orthodox Church holds to the teaching of synergy (συνεργός, meaning working together), which says that man has the freedom to, and must if he wants to be saved, choose to accept and work with the grace of God. Once baptised the experience of his salvation and relationship with God is called theosis. Mankind has free will to accept or reject the grace of God. Rejection of the gifts of God is called blasphemy of the Holy Spirit (gifts of grace, faith, life). The first who defined this teaching was John Cassian, 4th-century Church Father, and a pupil of John Chrysostom, and all Eastern Fathers accept it. He taught that "Divine grace is necessary to enable a sinner to return unto God and live, yet man must first, of himself, desire and attempt to choose and obey God", and that "Divine grace is indispensable for salvation, but it does not necessarily need to precede a free human choice, because, despite the weakness of human volition, the will can take the initiative toward God.".