Many Christian apologists through the centuries—and most American apologists right up to today—see miracles as proof. If faced with an event that can only be explained through supernatural power, people will be compelled to believe, it seems. Through miracles God proves his existence and power.
In The Supernatural Power of a Transformed Mind, Bill Johnson says that “one of the major functions of miracles and supernatural living is to offer immediate, irrefutable proof.”  And he suggests that evangelism without the power of “proof” is weak and ineffective.
This seem to be supported by John’s gospel, where Jesus says,
–“The miracles I do in my Father’s name speak for me.” (10:25)
–“Believe the miracles, that you may know and understand that the Father is in me….” (10:38)
–“Believe me when I say that I am in the Father and the Father is in me; or at least believe on the evidence of the miracles themselves.” (14:11)
–“If I had not done among them what no one else did, they would not be guilty of sin. But now they have seen these miracles, and yet they have hated both me and my Father.” (15:24)
I’ve been reading Colin Brown’s classic Miracles and the Critical Mind, which is mostly a history of all that has been written about Christian miracles over the centuries. Brown notes that many Christians, beginning with Augustine, have seen miracles as signs and sacraments rather than proofs. I found it a helpful distinction. Signs point to something but they don’t prove anything. If a sign on the freeway tells me that Santa Rosa can be reached by the next seven exits, it does not prove that I have reached Santa Rosa. Rather it invites me to get off the freeway and see for myself.
If miracles provide proof, many people seem impervious to it, both in Jesus’ day and ours. Most of the great philosophic minds past and present doubt that miracles offer irrefutable proof. When people try to investigate miracles after the fact—and there have been many attempts, over the years, to follow up on miraculous reports—they generally are left with more doubt that certainty. Miracles might seem to offer proof, but in fact they very rarely function that way.
But they do operate as signs. Miracles in the Bible, and miracles today, both point toward God’s kingdom coming to earth. So do many other things: love, preeminently, making itself known in different ways. If you follow the signs, you won’t get lost.