The greatest proof of God are the miracles, including the resurrection. Only God could suspend the laws of nature in such a way as to, for instance, raise Lazarus after his being four days dead in a hot environment. Consider Jesus’ own reply to this question:
24 The Jews who were there gathered around him, saying, “How long will you keep us in suspense? If you are the Messiah, tell us plainly.”
25 Jesus answered, “I did tell you, but you do not believe. The works I do in my Father’s name testify about me,
[From John 10]
If Jesus Himself says the miracles are the key to faith, we can take it to be that was their purpose. Also notice the miracles themselves were never disputed in Jesus’ day. The Pharisees condemned him for working miracles on the Sabbath, while the multitudes flocked to Him in hopes of seeing miracles. When it comes to Lazarus, here is the Pharisees’ & Sadducees’ response:
47 Then the chief priests and the Pharisees called a meeting of the Sanhedrin.
“What are we accomplishing?” they asked. “Here is this man performing many signs. 48 If we let him go on like this, everyone will believe in him, and then the Romans will come and take away both our temple and our nation.”
[From John 11]
Note that no one disputed the miracles—not even the raising of Lazarus. Rather, they realized that if Jesus kept it up, the whole world would believe.
God the Father cited miracles in a similar context:
Numbers 14:11
The Lord said to Moses, “How long will these people treat me with contempt? How long will they refuse to believe in me, in spite of all the signs I have performed among them?”
If God Himself argued His existence on the basis of miracles/the suspension of the physical laws of the universe, then it is the case that faith is meant to be founded upon them.
In other words, if the evidence of Jesus’ resurrection from the dead were not so historically sound, we would not believe. But the evidence for His resurrection is overwhelming, & it is the cornerstone of our faith.