The way we speak about salvation matters. One small word, mishandled, can distort the entire order of God’s saving work. That word is "could." Many describe unbelievers as those who could have believed in Christ but refused. On the surface, this appears to safeguard responsibility. In reality, it subtly denies man’s spiritual inability and God’s sovereign grace. Scripture teaches the opposite: apart from the Spirit’s work, the only thing fallen man can and will do is rebel.
Acts 13:48 removes all ambiguity: "And as many as were appointed to eternal life believed." The Greek verb tetagmenoi ("had been appointed") is a perfect passive participle. The appointment was already in place before belief occurred. The order is ironclad: appointment precedes belief. Luke does not write, "as many as believed were appointed," but the reverse. Faith is not the ground of God’s choice; God’s choice is the ground of faith. This sequence ends all talk of sinners who could have believed on their own.
Scripture insists that fallen man has no capacity for saving faith. "The natural person does not accept the things of the Spirit of God… he is not able to understand them" (1 Corinthians 2:14). "No one can come to me unless the Father who sent me draws him" (John 6:44). "You were dead in trespasses and sins" (Ephesians 2:1). Dead men do not could. They do not hover in a neutral state of possibility. Left to ourselves, the only thing we can and will do is rebel. As Romans 3:11–12 declares: "No one understands; no one seeks for God. All have turned aside… no one does good, not even one."
At best, sinners may express a simple belief—mere assent to facts. "Even the demons believe and shudder" (James 2:19). But effectual belief that saves is entirely different. It is the faith granted by God that unites a sinner to Christ. "By grace you have been saved through faith. And this is not your own doing; it is the gift of God" (Ephesians 2:8–9). "It has been granted to you that for the sake of Christ you should not only believe in him but also suffer for his sake" (Philippians 1:29). The faith that saves is given, not produced.
This is where God’s glory shines. His justice is magnified in condemning those who persist in unbelief, because their unbelief is willful rebellion. Their judgment is just, not because they could have mustered faith, but because they continually reject the light they do have (Romans 1:20). His mercy is magnified in granting faith to those who otherwise never would and never could believe. God rescues the helpless, raises the spiritually dead, and creates faith where only rebellion existed before.
The problem of "could" is that it smuggles human ability into the doctrine of salvation. To say unbelievers could have believed apart from God’s appointment contradicts Acts 13:48. To suggest sinners could generate saving faith denies John 6, 1 Corinthians 2, and Ephesians 2. The truth is stark: apart from grace, the only thing we can and will do is rebel. Faith is the condition of salvation, but it is a condition God Himself supplies.
Thus God is glorified both as righteous Judge, condemning rebels who persist in unbelief, and as merciful Savior, granting the very faith no sinner could ever produce.
The word "could" belongs not to man’s imagined ability, but to God’s sovereign grace: "God could raise up children for Abraham from these stones" (Matthew 3:9).
He alone makes the impossible possible.