Jesus had conferred upon his disciples the power to work miracles of healing; but their failure in this case, before so many witnesses, had deeply mortified them. When they were alone with Jesus they asked him why it was that they were unable to cast out the devil. Jesus answered that it was because of their unbelief, and the carelessness with which they regarded the sacred work that had been committed to them. They had not fitted themselves for their holy office by fasting and prayer. It was impossible for them to vanquish Satan except as they received power from God; they should go to him in humiliation and self-sacrifice and plead for strength to conquer the enemy of souls. Nothing but entire dependence upon God, and perfect consecration to the work, would insure their success. Jesus encouraged his disappointed followers in these words: “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.” {2SP 335.3}

Jesus havde givet sine disciple magt til at helbrede og gøre mirakler; men de blev meget skamfulde over deres uduelighed i dette tilfælde i så mange vinders påsyn. Jesus svarede, at det var på grund af deres vantro og den ligegyldighed, som de viste overfor den hellige (336) gerning, der var dem betroet. De havde ikke beredt sig selv til deres hellige embede ved faste og bøn. Det var dem umuligt at overvinde Satan, uden de fik magt fra Gud. De skulle gå til ham i ydmyg selvfornægtelse og bede om styrke til at overvinde sjælefjenden. Intet uden fuldkommen tillid til Gud og opofrelse i deres gerning kunne give dem sejr. Jesus opmuntrede sine skuffede efterfølgere: "Hvis I har tro som et sennepsfrø, kan I sige til dette bjerg: "Flyt dig herfra og derhen," så skal det flytte sig; og intet vil være umuligt for jer" (Matt 17,20)