Please name these many Christian scientist who have made useful contributions and what there contribution was.

It boils down to Occham's razor. You don't add anything to a study that doesn't add any value. People used to think lightening strikes were a result of God's anger. Ben Franklin developed the lightening rod and essentially eliminated that argument. Science cannot say God did it because historically it ends the search. So, it is good to leave God out and if there is a God he hides himself anyway. Disease was thought to be caused by Satan or original sin or sin we just did in the Christian frame. Turns out it is micro-organism. If we kept God in the study that would not have been discovered. Christianity has a long history of persecuting scientist, even today they fight stem-cell research. They need to stay out of it if we sincerely want progress.