The Bible contains some a fortiori arguments. And that’s a really good thing, for at least two reasons. These arguments mean that God is abundant in his grace. There’s a lot of “more” in his how much more’s! They also mean that he lovingly refuses to strike a truce with our doubts and low-level confidence in his greatness and his goodness. He knows us and loves us enough to argue us into confidence in Him.
Consider two examples. Both of these a fortiori arguments are of the a minore ad maius (from the lesser to the greater) variety. Both of them are found on the lips of Jesus.
25 "Therefore I tell you,
do not be anxious about your life,
what you will eat or
what you will drink,
nor about your body,
what you will put on. …
26 Look at the birds of the air:
they neither sow nor reap nor gather into barns,
and yet your heavenly Father feeds them.
Are you not of more value than they? (lesser to the greater)
28 And why are you anxious about clothing?
Consider the lilies of the field, how they grow:
they neither toil nor spin,
29 yet I tell you,
even Solomon in all his glory
was not arrayed like one of these.
was not arrayed like one of these.
30 But if God so clothes the grass of the field,
which today is alive and
tomorrow is thrown into the oven,
will he not much more clothe you (lesser to the greater),
O you of little faith?
Jesus argues like this again in Luke 11:11-13:
11 What father among you,
if his son asks for a fish,
will instead of a fish give him a serpent;
12 or if he asks for an egg,
will give him a scorpion?
13 If you (the lesser) then, who are evil (the evil lesser, for that matter!),
know how to give good gifts to your children,
how much more will the heavenly Father (the greater/Greatest!)
give the Holy Spirit to those who ask him!"
Do you see how these are supposed to “work” in our hearts? They are intended to give us a loving, look-us-in-the-eyes, spiritual “Of course!” moment. We should come away saying, “What was I thinking? How insane am I not to trust GOD, but trust in my(untrustworthy)self or some other fickle human or false promise! Good grief! If he takes care of birds… If he clothes THE GRASS… If WE know how to give good things…!”
All praise to this patient, slow-to-anger, abounding-in-steadfast-love-and-faithfulness, a fortiori God! The a fortiori God is full of a fortiori grace for weak sinners like us who are spring-loaded to downsize his grace and supersize the false promises of sin; to downsize his trustworthiness and supersize our doubts.
He knows we need Him to bombard those supersized facades with gospel explosives (see 2 Cor. 10:4-5), so that they stop blocking our view of his surpassing worth. So, he launches his a fortiori arguments. And every one of those gospel smart bombs is launched from the cross. The cross is the greatest a fortiori argument of all. It sets up THE argument of arguments. The a fortiori a maiore ad minus – from the greater to the smaller – of Romans 8:32:
He who did not spare his own Son but gave him up for us all (the greatest, the hardest thing), how will he not also with him graciously give us all things (“giv[ing] us all things” is the easy thing, the lesser thing!)?
THE argument of arguments is the proof that every other a fortiori argument he levels on our unbelief is true. Ponder and believe his lesser-to-the-greater grace! And savor the fact that every ounce of lesser-to-the-greater grace was secured by the greatest greater-to-the-lesser argument in all the universe!