Jesus said unto him, If thou canst believe, all things [are] possible to him that believeth.
Berean Study Bible (BSB) - Mark 9:23 >“If You can?” echoed Jesus. “All things are possible to him who believes!”
Textus Receptus (TR) - Mark 9:23 >Ὁ δὲ Ἰησοῦς εἶπεν αὐτῷ, Τὸ εἰ δύνασαι πιστεῦσαι, πάντα δυνατὰ τῷ πιστεύοντι.