I answer the same way I usually do about this question.
Are you asking for the scientific method to be applied to test God's presence? If so, then I doubt I can give a satisfying answer because it's comparing apples to oranges. It's not a good technique in this situation. For example, the scientific method doesn't prove that a song is good, a landscape is serene, or a picture is lovely.
It's not a matter of faith in God's existence. Faith applied in the modern way seems so bizarre. It's as though I'm asked to believe something contrary to scientific evidence. I don't have faith this way. This is faith in antagonism with scientific methodology. My faith is irrespective and independent of scientific methodology because the aforementioned inappropriateness of the test.
Without any testing, however, I witness evidence of God every day.
- I hear a good song
- I walk a serene landscape
- I view a lovely picture
These tests work for me, they matter to me and they give me faith to know that there is something indefinable operating somewhere out there.