By what means do we become Christians? Through our faith would be the universal answer. And in what way are we saved? Plainly because we were regenerated through the grace given to us in our baptism. How else could we be? And after recognizing that this salvation is established through the Father and the Son and the Holy Spirit, shall we fling away “that form of doctrine” which we received? Would it not rather be grounds for great groaning if we are found now further off from our salvation “than when we first believed,” and deny now what we then received?

–Basil the Great, On the Holy Spirit 10.26