If Jesus meant what he said there should be a number of provably miraculous healings and resurrections among Christians and their families. Why isn't there?
Because you cannot prove what is supernatural, it is beyond scientific understanding, it is outside of the laws of nature.
www.oxforddictionaries.com/definition/english/supernatural?q=supernatural
If someone does not believe in the supernatural, the explanation they would give is that a physical manifestation is spontaneous or merely unexplained.
The same things I find valuable about my life in general now such as mutual support of friends. What's clear are that the elements that I thought made me a Christian are actually just the elements that make us all intelligent humans such as kindness and acceptance
Of course intelligent (and unintelligent, for that matter) human beings can be kind and accepting. I believe these are good qualities and according to my belief they come from God and anyone might possess them as we are made in His image. I don't attribute them to intelligence, although I believe it can be clever to be kind and accepting of others.
I think pursuing Christian belief gives additional opportunity to think about these qualities, in a systematic, but also organic way though. But again I don't believe you can compare - I am always very wary of statistics in the social sciences too and also quite cautious in terms of medical research. The one exception is still meaningful for that individual who is the exception.