Read Mark 9.14-29
One day, all but three of Jesus' disciples were out ministering to the people. Jesus had been teaching them, and they were doing pretty good. Until a man showed up to them with his son. There's no way to say for sure, but it sure sounds to me like the son had epilepsy. No word on whether he was a boy, or if he was an adult who could never leave his parents' home. Whatever it was for sure, it was a big problem.
The man heard that Jesus' disciples were somewhere in town, and they were healing lots of sick or injured people. So he headed down there with his son as quickly as possible. One of the disciples stepped up in confidence, and asked what the problem was. The man told him the same thing he told Jesus later. "...he has a spirit that makes him mute. And whenever it seizes him, it throws him down, and he foams and grinds his teeth and becomes rigid." So one disciple after another tried to cure this boy. Then they probably teamed up to be stronger. The formulas they had learned weren't doing anything. Then somebody started to complain. The disciples argued back. Finally, Jesus and the other three disciples showed up from where they had been.
Nine of Jesus' direct disciples-- maybe some other, less central disciples with them-- failed miserably, and got all stirred up about it against each other. Kinda like a 21st century Church that I know about.
So what was their problem? No faith? No, they had faith. They understood the power to do this healing. Experience? Not a lot, but they had healed someone else who was like this before. Just imagine these guys trying to deal with this, "What in the world are me missing here?"
Jesus saw the fight, and asked what was going on. The kid's father told him the story, probably in tears. Then he gave away his main problem, which infects almost all people to this day. "If you can do anything," he said, "have compassion on us and help us."
Jesus response? "'If you can!' All things are possible for one who believes." Basically saying that He would have no problem with it. And the man got it. After a whole life of going through the official processes that he had been taught. Doing religion "right." Praying for the wrong reason. "I believe; help my unbelief!" Or, more modern English: "I believe you can! Help me truly believe that you can work through others like me!" Then Jesus turned to the boy, gave orders, and the boy was healed.
Afterward, Jesus' disciples asked why they weren't able to heal that boy. Jesus' answer was a surprise to them. It wasn't about experience. It was their connection of faith with power. They had gotten so positive about healing others, they were forgetting the most important part. In my haggard mind, I think that as the day passed, fewer and fewer were actually being healed. Wrapped up in "their" healing work, "their" confidence got shifted to "their" power. They had forgotten that their actual power level was zero. All the power is of God.
Their attitudes were slowly changing. They thought they had great power and authority to do everything, and God would give permission to them. It was so easy for Jesus to explain. "This kind cannot be driven out by anything but prayer." They had started doing their ministries backwards, and Jesus was pulling them back around. Ask God to provide the power and authority, and have faith that God will do it through you as you follow Him.
Personal action and power, back-supported by faith in God, to heal somebody for Church reputation? That's wrong.
God's action and power, asked to act through faith in God, to bring that person and many others to God.