It's not a matter of faith whether or not Jesus existed. There's overwhelming evidence from eyewitnesses and those who talked to eyewitnesses that Jesus lived. There's also the evidence of the miracles themselves and how that affected people. The church went from about 120 to over a million in less than 40 years.
(Luke 1:1-4 NIV) Many have undertaken to draw up an account of the things that have been fulfilled among us, {2} just as they were handed down to us by those who from the first were eyewitnesses and servants of the word. {3} Therefore, since I myself have carefully investigated everything from the beginning, it seemed good also to me to write an orderly account for you, most excellent Theophilus, {4} so that you may know the certainty of the things you have been taught.
(2 Peter 1:16 NIV) We did not follow cleverly invented stories when we told you about the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty.
Paul was an enemy of the church until Jesus confronted him on the road to Damascus. His story is perhaps the most convincing one when it comes to Jesus.
(Acts 26:10-18 NIV) And that is just what I did in Jerusalem. On the authority of the chief priests I put many of the saints in prison, and when they were put to death, I cast my vote against them. {11} Many a time I went from one synagogue to another to have them punished, and I tried to force them to blaspheme. In my obsession against them, I even went to foreign cities to persecute them. {12} "On one of these journeys I was going to Damascus with the authority and commission of the chief priests. {13} About noon, O king, as I was on the road, I saw a light from heaven, brighter than the sun, blazing around me and my companions. {14} We all fell to the ground, and I heard a voice saying to me in Aramaic, 'Saul, Saul, why do you persecute me? It is hard for you to kick against the goads.' {15} "Then I asked, 'Who are you, Lord?' "'I am Jesus, whom you are persecuting,' the Lord replied. {16} 'Now get up and stand on your feet. I have appeared to you to appoint you as a servant and as a witness of what you have seen of me and what I will show you. {17} I will rescue you from your own people and from the Gentiles. I am sending you to them {18} to open their eyes and turn them from darkness to light, and from the power of Satan to God, so that they may receive forgiveness of sins and a place among those who are sanctified by faith in me.'
Paul said this about how many people saw the resurrected Christ.
(1 Corinthians 15:3-8 NIV) For what I received I passed on to you as of first importance : that Christ died for our sins according to the Scriptures, {4} that he was buried, that he was raised on the third day according to the Scriptures, {5} and that he appeared to Peter, and then to the Twelve. {6} After that, he appeared to more than five hundred of the brothers at the same time, most of whom are still living, though some have fallen asleep. {7} Then he appeared to James, then to all the apostles, {8} and last of all he appeared to me also, as to one abnormally born.