What proof do you want to believe in God? Do you want a scientific proof or a proof by logic? Do you want a big miracle? Like solving climate change, so we can continue our wasteful and polluting life styles? God did a big climate-change thing long ago (Genesis 7), but people still didn’t believe, so why should it be different now? Perhaps God should drop food from heaven to eliminate hunger? God did that also long ago (Exodus 16), and people still didn’t believe! How about God should bring back from the dead someone you loved who died too young? God did that also (Luke 7:11-15), and people still didn’t believe. Or perhaps you just want some display of power. Like dividing the Red Sea (Exodus 14). But we know how quickly people forgot about that show of power!
God gave up trying to impress people and chose another way. God answered Thomas’ doubts with the wounds of Christ. Here, touch and see – not some spectacular show of power, but the wounds of humanity. And those wounds have now become God’s wounds! That’s the proof that God offers. And it should be all the proof we need. No miracles or displays of power that can be ignored or explained away by inconsequential explanations. The proof that God offers is the miracle of a love that bears the marks of all human pain and suffering. That’s the God I believe in. It’s the only God worth believing in!
Ancient Answers 
It is quite amazing that you expressed these thoughts, because i have been thinking recently about why today’s church seems to have lost the evident display of miracles.
I think God delights in teaching us how to search for Him and His will. In John 8:32 Jesus promises that people will know the truth , and the truth shall set them free; but to quote Pilate the question remains: ” what is Truth? ”
You discussed in your thoughts, God’s perspective for this question, as you searched for what proof God can give. I think that the theologies people believe in reflects what they believe in. If they are vengeful, they believe in a vengeful God, if they are forgiving they believe in a forgiving God. I think that a God that bears the burdens of human pain and suffering as you put it, shows a compassion that is the noblest quality of human existence, that is to feel the pain of others, and concentrate on their sufferings rather than the narcistic pleasure of satisfying self, and I agree, this is the God of the Biblle and my God. However, i think the search for God is almost as significant as the finding. Thomas wanted proof., so when he was at the right place on the right day he found truth. Truth, to him was extraneous. I think that God would like us to find the remains of the image he created in us, and in that find out who He truly is. To do so, he has to remain hidden…because otherwise we will keep looking in the wrong place for the miraculous.