Yes, but some Christians do believe they have experience of God and that they do have evidence of their experience. Since I haven't experienced it I can't write it off. I think science is used a reason for not believing but that science is often based solely on the values and workings of the earth science where things are replicable and every time you look for evidence you get the same evidence. Atoms, molecules, rock gases etc, they all react the same way for a certain set of circumstances.
The life sciences like biology and experimental psychology don't have the absolute answers. Things can't be replicated the same way. I can't live my life twice in parallel to see what happens in one set of circumstances and not another. Because of that I can't say for sure that ones person's experience that they believe to be related to God is false just because I don't have the same experience or react the same way. This kind of science only works on probabilities and therefore leaves room for doubt and uncertainty.
I also don't believe that science has all the answers. There is still an awful lot of work to be done on what actually makes consciousness, which can't be solved simply by looking at how the brain works. Anything emotional can't be explained fully by electrical impulses in the brain or we would have been able to replicate in inanimate objects. Computers can't have consciousness or feel love not matter how close an approximation humans can create.
Because of that gap in what is provable and what is not, there is room for a God. I don't see him, I don't feel him, I have no knowledge of him but I can't discount the possibility of him being there.
That was probably really badly put but I don't get the idea that only science has all the evidence, that it has any absolute certainties as far as humans are concerned.
And yes it is different believing God to believing in the spaghetti monster in the sky or whatever patronising nonsense some people trot out because of the experience of some people who belive they have felt God. Nobody, well not enough to make it a relevant sample, has felt the existence of the spaghetti monster, plenty more believe they have evidence of God which for the reasons stated above cannot be entirely discounted.