Jesus says you already have enough evidence of God’s existence and of your need for a savior to give you no excuse for unbelief. So even if you were to see a miracle, it wouldn’t take you from a position where you didn’t have enough evidence to one where you did; it would make no difference to your present situation. What will convince you, then?
We see that there is no problem with the evidence - the problem is in your heart:
God tells you in His Word that Jesus is the only Savior He has given Who can change this situation if you will trust in Him. Isn’t it time to repent and believe?