With What power Iam doing Miracles?

The Fig Tree Withers
Early in the morning, as he was on his way back to the city, he was hungry. Seeing a fig tree by the road, he went up to it but found nothing on it except leaves. Then he said to it, "May you never bear fruit again!" Immediately the tree withered.
When the disciples saw this, they were amazed. "How did the fig tree wither so quickly?" they asked.
Jesus replied, "I tell you the truth, if you have faith and do not doubt, not only can you do what was done to the fig tree, but also you can say to this mountain, 'Go, throw yourself into the sea,' and it will be done. If you believe, you will receive whatever you ask for in prayer."
The Authority of Jesus Questioned
Jesus entered the temple courts, and, while he was teaching, the chief priests and the elders of the people came to him. "By what authority are you doing these things?" they asked. "And who gave you this authority?"
Jesus replied, "I will also ask you one question. If you answer me, I will tell you by what authority I am doing these things. John's baptism—where did it come from? Was it from heaven, or from men?"
They discussed it among themselves and said, "If we say, 'From heaven,' he will ask, 'Then why didn't you believe him?' But if we say, 'From men'—we are afraid of the people, for they all hold that John was a prophet."
So they answered Jesus, "We don't know."
Then he said, "Neither will I tell you by what authority I am doing these things.