Thus we see how splendid a thing Baptism is. It snatches us out of the devil's jaws, makes God our own, defeats and puts away sin, daily strengthens the new man in us, keeps functioning, and remains with us until we leave our present troubles to enter glory everlasting.
Everyone should therefore look upon his Baptism as his everyday wear, to be worn constantly. He should at all times be found in faith and surrounded by its fruits. He should every day suppress the old man and grow toward maturity in the new man. For if we want to be Christians, we must carry on in the work that makes us Christians. But if someone falls away from it, let him come back to it again. For just as Christ, the throne of divine mercy, does not withdraw from us nor prevent us from coming back again to Him, though we sin, so also all His treasures and gifts remain.
Martin Luther, from the Large Catechism, page 218 in "For All the Saints" volume one.