There are those who say that if they saw the miracles that happens in the time of Moses, or the disciples they would surely have faith.
What are the Biblical reasons for miracle? Is it to create faith?
Preface: this is a generalization. Atheists, like Christians, can't simply be lumped into a group where all of them think, act, react, and believe the same way.
I don't believe so. In the words of Jesus Himself,in Matthew 16:1-4 (KJV)
In this case, Jesus was specifically dealing with the hypocritical "spiritual leaders' of the day, but I believe that the lesson can just as easily be applied to those who don't believe at all. The problem with the Pharisees and the Sauducees was that they didn't believe and that they didn't want to believe because believing that Jesus was the messiah, the son of the living God, would have upset their world-view. They were comfortable in their beliefs.
With most atheists that I've rubbed shoulders with (or even myself when I was one) the problem is only partly that we have no proof of God's existence. The other half of the problem is that we would reject the proof if we saw it.
As reference for this last statement, go back and search this site for questions on miracles - why are there no miracles seen today, and other similar questions, and read the comments. If you do, you'll see that the atheists asking here pretty much reject any miracle as coincidence, or something explainable via non-miraculous means.
Additionally, non-atheists from other religions wouldn't necessarily be convinced by miracles. The Old Testament is filled with stories of other nations seeing the miracles of God, but still worshiping their own idols and gods.
Good question, but
Miracles do not cause people to believe
Luke 16 contains the story often called "The Rich Man and Lazarus" or "Dives and Lazarus" in older times.
The gist of the story is that a rich guy (rich is 'Dives' in Latin, pronounced Div' - ees) dies and goes to hell. Once there, he really, really doesn't like the place, and begs Abraham to be able to go back and tell his brothers to change course, lest they end up there with him. His reasoning is simple - surely a miracle would prove to them that they need to repent!
In other words, Dives is making the case that if a miracle were given, then clearly people would believe and repent. Abraham is, however, proved exactly right every day, however, in that Jesus did come back from the dead [I know somebody is going to disagree with me on that!] and yet people didn't listen to him either.
As God cries out in Isaiah 65:2,
Miracles do not accomplish what God wants
In the end, however, if "seeing is believing," then seeing would ultimately be counter-productive, because God explicitly desires faith. And faith, as we know is the evidence of things hoped for - the rebuke / the real proof (my translation) of things not seen. (Heb 11:1) Jesus says as much to Thomas, after the miracle of the resurrection, in John 20:29 when he says:
And as it says in Hebrews 11:6
In other words, miracles might "prove" something, but God doesn't want to overwhelm us - he wants us to believe on our own.
So then, why are miracles given at all?
Miracles are given in order that we might believe (Mark 2:9-10). They are signs that God is in fact behind a thing. Jesus forgave a lame man's sin, and the Pharisees grumbled. So, Jesus says, "in order that you might know that I have authority to forgive sin..." he performs a miracle.
The problem, of course, is that then people want miracles not as evidence but rather for gain. Herod wanted Jesus to perform tricks in order to prove his god-hood, but Jesus would not.
Ultimately the best indictment, however, comes from Luke 11:28 -32
The definition of faith: To believe in something that is not seen but is true.
Miracles were provided after faith to confirm ones faith. So many wonderful things happened during the time of Moses and yet... The children of Israel wondered in the desert for 40 years, worshiped idols and would not look upon the raised up snake to save themselves. Why? Because they didn't have faith so no mater how many miracles they saw it was not enough to 'give' them faith.
So to answer your question no miracles are not to give faith. They never have been and they never will be. Things that are seen are forgotten (above example of the Israelite's coming out of Egypt) which is why faith is confirmed by the Holy Ghost.
Aside: I find the idea that faith is only possible with a lack of evidence to be unconvincing. There are plenty of places that that falls down within Christian ideology. Consider the apostles' faith, for example.
No, faith is simply a conviction that something is or will be. The faith can be blind or it can be guided, but it's still faith. Even Doubting Thomas had faith. So he was "less blessed", whatever that means, but that doesn't matter in the long run.
Anyway, to answer the question: many of the miracles of the times of Moses are trivial to reproduce in modern day with modern illusion, trickery, and technology. We are a much more learned people today. The miracles would have to be much greater in scope. Or perhaps more personal in scope. An identical revelation to all people on Earth simultaneously would be convincing to many, I'm sure.
So I'm going to give this a tentative yes.
If you believe what people say, the answer is clearly "yes, some more would believe". One can with little trouble find discussions just like this on various forums. (Here's one regarding conversion of atheists.) If you believe what people say, the answer is again clearly "yes" given that some people say they did convert because of miracles. (Another example, this time converting from Islam.)
Then the question is: can you believe what people say?
There are at least three reasons for miracles.
Therefore, yes, miraculous works can help bring more people to the faith.
Jesus said (John14:11)
Does it matter whether someone believes because of a testimony vs. a miracle? A sheep is a sheep whether it walks through the gate or is carried.
P.S. Jesus miraculously appeared to doubting Thomas with the stated goal of producing faith.