Jesus said to him, If you can believe, all things are possible to him that believes.
If.
Mark 11:23 For verily I say unto you, That whosoever shall say unto this mountain, Be thou removed, and be thou cast into the sea; and shall not doubt in his heart, but shall believe that those things which he saith shall come to pass; he shall have whatsoever he saith.
2 Chronicles 20:20 And they rose early in the morning, and went forth into the wilderness of Tekoa: and as they went forth, Jehoshaphat stood and said, Hear me, O Judah, and ye inhabitants of Jerusalem; Believe in the LORD your God, so shall ye be established; believe his prophets, so shall ye prosper.
Matthew 17:20 And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.
“All things are possible to him who believes!”
This statement by Jesus emphasizes the limitless potential of faith. In the biblical context, faith is not merely intellectual assent but a deep trust in God's power and goodness. This teaching is consistent with other scriptural passages, such as Matthew 17:20, where Jesus says that faith as small as a mustard seed can move mountains. Theologically, this phrase points to the omnipotence of God and the believer's access to that power through faith. Historically, this teaching would have been radical, as it shifted the focus from human limitations to divine possibilities. It also foreshadows the greater works that believers would do through faith in Jesus, as mentioned in John 14:12. This phrase serves as a call to believers to trust in God's ability to work beyond human understanding and circumstances.
The distraught father cried, “But if You can do anything, have compassion on us and help us” (Mark 9:22). Jesus purposely repeats the man’s own words, spotlighting the tiny seed of unbelief behind them.
• Doubt puts a question mark where God has placed a period (James 1:6–7; Matthew 17:20).
• Earlier a leper said, “If You are willing” and Jesus answered by touching and cleansing him (Mark 1:40–41). The issue is never the Lord’s ability.
• The moment Jesus echoes the phrase, every ear in the crowd hears how small faith sounds when spoken aloud.
By mirroring the father’s words, the Lord both confronts and invites.
• Confronts: Jesus often exposes wavering faith to call people higher (Matthew 14:31; Luke 24:38).
• Invites: His tone is not harsh but corrective, steering the man from “if” to certainty (Mark 8:17–18).
• The echo serves as a gentle rebuke—yet it keeps the conversation open, drawing the father toward trust rather than shame.
With the doubt uncovered, Jesus replaces it with a sweeping declaration: “All things are possible.”
• God’s capability is unlimited (Genesis 18:14; Jeremiah 32:17, 27; Luke 1:37).
• Nothing—from healing a child to raising the dead—is beyond His reach (Mark 10:27; Ephesians 3:20).
• The phrase resets the father’s focus from the demon’s stubbornness to the Lord’s omnipotence.
The promised possibility is tied to faith, not wishful thinking.
• Faith is confidence in God’s character and Word (Hebrews 11:6; John 11:40).
• Belief appropriates what God is willing and able to do (Matthew 21:22; 1 John 5:4-5).
• The father immediately responds, “I do believe; help my unbelief!” (Mark 9:24), showing that imperfect faith, honestly offered, is enough for Jesus to act.
Jesus turns a hesitant “if” into a triumphant certainty. By echoing the father’s words, He exposes doubt, then floods the moment with divine possibility, anchoring it all in believing trust. Mark 9:23 teaches that God’s power has no limits, and faith is the open door through which that power flows into real-life needs.
(23) If thou canst believe.--The better MSS. omit the word "believe," and the sentence without it is taken as expressing the sadness of surprise. Our Lord repeats the half-believing, half-despairing words of the father in a tone of sadness, If thou canst. . . . Was this the way in which a man should speak who came to Him as a Healer? Such a one had to learn the great primary lesson that "all things were possible to him that believeth," that the secret of previous failure lay, in part at least, in his own want of faith, as well as in that of the scribes and disciples who had tried their arts of exorcism in vain.Verses 23, 24. - The most approved reading here is, not Αἴ δύνασαι πιστεῦσαι, but simply Αἴ δύνασαι, So that the English rendering is, If thou canst! All things are possible to him that believeth. Our Lord takes up the father's words. It is as though he said, "Thou sayest to me, 'If thou canst do anything!' Ah, that 'If thou canst!' All things are possible to him that believeth." In other words, our Lord said to him, "Believe in me, and your child shall be healed." It was right that Christ should demand faith in himself; for it was not fitting that he should confer his special benefits on those who disbelieved or doubted about him - that he should thrust his blessings on those who were unworthy of them. The answer of the father is touching and beautiful. Greatly agitated, he cried out and said (we might well suppose (μετὰ δακρύων "with tears," although the weight of evidence is against this addition being retained in the text), I believe; help thou mine unbelief. It is as though he said," I do believe; but my faith is weak. Do thou, therefore, increase and strengthen it; so that whatever there is in me of doubt or remaining unbelief may be taken away, and I may be counted worthy to obtain from thee this blessing for my son." Nor can we doubt that Christ heard a prayer so humble and so fervent, and took away from him the last remains of doubt and unbelief.