You keep using that word [logic]: I do not think it means what you think it means.

From Francis Collins, who argues the following as scientific evidence for God:

An additional set of observations I found quite breathtaking and do to this day is the fact that the physical constants that determine the nature of interactions between matter and the way in which energy behaves have precisely the values they would need to have for any kind of complexity or life to occur.

I interpret the argument to be thus:
(1) the physical constants necessary to support life are extremely rare
(2) because the life exists, then God must exist.

I am skeptical that (1) is true, since we don't know ANYTHING about extraterrestrial life to say what could or could not be supported by different physical constants. It is outside our realm of knowledge to say that lifeform X could not exist under conditions Y because we don't know about all the different types of X or even all the different types of Y.

But for argument's sake, let's suppose you accept (1). Then you hit the BIG logical fallacy:

Because life exists (and the conditions to support life are astronomically rare), God must exist.

Which is completely ass-backwards, because the logical sequence of events is:

God exists => the physical constants of the universe are tuned perfectly => life exists.

Since we are alive, this statement CANNOT be disproven. It can only be disproven if we find (a) perfect tuning of physical constants of the universe and (b) the LACK of life. By definition, it would seem difficult to both determine the physical constants of the universe while not being alive and also proving that no life existed elsewhere in the universe.

This is an extremely basic logical fallacy that I learned about in 8th grade in the math unit on logic, but I'm sure I had an intuitive sense of why this was incorrect earlier than that. Claiming that this is "scientific evidence" for God is just plain BS, cuz last I checked *real* scientists (and scientists-to-be) use logic.