So saving grace, converting grace, for Augustine, is God's giving us a sovereign joy in God that triumphs over all other joys and therefore sways the will. The will is free to move toward whatever it delights in most fully, but it is not within the power of our will to determine what that sovereign joy will be.
John PiperSpiritual leadership is knowing where God wants people to be and taking the initiative to get them there by God's means in reliance on God's power.
John PiperObedience does not consist in paying God back and thus turning grace into a trade. Obedience comes from trusting in God for more grace - future grace - and thus magnifying the infinite resources of God's love and power.
John Piper