The Bible is full of miracles. Miracles are important: you can
learn a lot from them.
Detail
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.