Thomas Bradwardine on Augustine’s comments on John 1:16,
“Does Augustine mean we receive faith before we receive grace? But we cannot walk in faith without being in grace. How would we every have received this grace? By our preceding merits? Grace is given to you, it it is not a payment. For this it is called grace, because it is freely given. With preceding merits you cannot buy what you have already received as a gift.
“God crowns His gifts, not your merits.”
Therefore the sinner has received first grace in order that his sins might be forgiven. What has he merited? When he demands justice he will receive punishment and when he asks for mercy he will receive grace. But this is exactly what had been promised by God through the prophets.
Therefore when He comes to give what He has promised He gives not only grace but also truth. How is this truth manifested? When that which has been promised is fulfilled. What, in fact does “grace for grace” mean (refering to John 1:16- J.F.)? By faith we merit God. That you received the immortal reward, that is eternal life, is grace. On account of what merit do you receive eternal life? On account of grace. “God crowns His gifts, not your merits.”
The Cause of God Against the Pelagians, 14th century, taken from Heiko A. Oberman, Forerunners of the Reformation: The Shape of Late Medieval Thought, pp. 156-157