Thus, taking its start from the thought of God’s benevolent care for you, you should doubt none of this. But if this foundation seems abstract to you, then look at how He granted us the gifts we have received. In order to grant them to us, He did not spare His Son. If He did not spare His Son, beyond which nothing higher or greater can be done for us, can you waver over whether He will give what has been promised? It cannot surpass this. He gave the greater. Will He not give the lesser?
Or again, He has granted much and promised more. But if still more should prove necessary and desirable, do not doubt that He will grant all that also, since He did not spare His Son for us.
St. Chrysostom says, “The Apostle speaks forcefully and with great ardor, in order to express God’s love. Will God abandon us, when He did not spare His Son for us, but delivered Him up for us all? Consider what goodness it is not to spare His own Son, but to deliver Him up. He delivered Him up for the worthless, the ungrateful, enemies, blasphemers. ‘How then shall He not also with Him freely give us all things?’ These words mean this. If God gave us His Son, and not only gave Him, but delivered Him over to be slain, then, having received the Master Himself as a gift, why do we still doubt concerning everything else? Having the Lord, can one entertain doubt about receiving the other gifts? He who gave enemies, when we were enemies, the greatest thing, will He not give friends, now that we have become friends, what is less important?”
Photius in Oecumenius touches on several other shades of the apostolic persuasion. “The Apostle added, ‘He who did not spare His own Son,’ and so forth, in order to show God’s ineffable care for us. He also did this so that, by this example, he might dispose us to patient courage when something grievous is suffered from others. Or, what is greater, he did it to inspire us and give us wings for sufferings. For if the Son suffered so much for your sake, how much ought you to suffer for His sake? And if He, after suffering thus, sustained no loss at all in the Father’s glory and Godhead, then do not lose heart when you suffer, as though you had been utterly diminished and robbed. Most certainly you will be counted worthy to receive the promise, both after sufferings and after death. Therefore he also added, ‘How shall He not also with Him freely give us all things?’ He wished to assure us that the promised gift can in no way, and under no pretext, be annulled. He says, ‘With Him He will freely give us all things.’ You may say, ‘What if He forgets us?’ But in that case He would also forget His Son. For He promises to give us all things with Him. Therefore, most certainly and without delay, we shall receive what was promised.”