And theologians about theology.
Scientists and their science are good and necessary. I want to begin there to avoid misunderstanding. I have a lot of respect for the work they do. It is important and our culture should be extraordinarily grateful for the ease with which we are able to live because of the work of scientists.
Secondly, I want to emphasize that science and Catholic Christianity are not opposites or even contradictory. (Divisiveness between Catholicism and Protestantism is not my intention here but I can only speak for what I know.)
Those things are necessary to say this: The opinion of scientists on points of religion should be taken very lightly, as lightly in fact as the opinion of theologians on points of science. (Theological commentary on the morality of various scientific achievements is a different matter. They are not speaking of the science itself but rather the implication and/or affects thereof.*)
Now, a scientist may have reasons for believing certain things about matters of religion and those opinions may come about based on what he has seen in his research but those opinions are exactly matters of his personal opinion that should remain distinct from his position as a scientist because they are not the direct result of his science.
This has to be the case because they are not experimenting on the truths of religion. They can't. Religion is lacking exactly the physicality that science deals in exclusively. They deal in different realms.
I'm not addressing specific statements by specific scientists on purpose because I'm not here talking about the rightness of wrongness of any particular opinion but just emphasizing that we ought to be careful about how much weight we give to whose opinions. We wouldn't want to be logically fallacious now would we? (Improper Appeal to Authority is a kind of logical fallacy.)
Earlier I said that I was only speaking from viewpoint of Catholicism because that all I know. That's exactly what I'm encouraging related to opinions of scientists, that and nothing more.
*A theologian criticizing stem cell research, for example, is concerned with whether or not it is right to do, not how it is done.