The Bible is full of miracles. Miracles are important: you can learn a lot from them.
I often meet Christians who seem to think that the main reason why we should pray for miracles is so that we can use them to 'prove' to our unbelieving friends that God is real and answers prayer.
It seems to me that this approach is completely mistaken. God does miracles because He loves us, not as a tool to support our evangelistic strategy.
Every miracle Jesus did was a one-off blessing, or a short term fix.
I cannot think of a single miracle in the Bible that is performed as a witness - that is, done with the purpose of persuading or convincing unbelievers. In fact, offhand I can only think of two miracles in the Bible that are given as a witness to believers.
Every other miracle is done as an expression of God's goodness and love - it communicates His character through helping people in practical ways.
Yes, miracles also demonstrate God's power. But if they were intended to be demonstrations to unbelievers, they would not be temporary in nature. Heal someone, and they will get sick again; raise the dead and they will only die sooner or later. A few minutes, days or weeks after the healing, and most people will have forgotten about it. As a reminder of God's power, it would have been much more effective to turn someone's hair green: that would have reminded them every day for the rest of their life.
As an exercise, contrast the miracles of Jesus with the miracles that Krishna is supposed to have done. To take just one typical example: Krishna, the story goes, lifted a whole mountain and balanced it on one finger. The whole story sounds rather silly to me, but perhaps that is just my cultural inheritance at work. In any case, as a story to demonstrate the power of Krishna, it certainly communicates. As a demonstration of character however, it's a bit more lacking. You just can't imagine Jesus doing that sort of thing. Jesus had power, but He never used it like that.
You don't need to listen to the teaching: just compare the miracles. You will see the difference.