If we don't know how this works, then how confident are we in saying things like the universal constants that we have observed for the last 200 years are indeed constant and have never changed?
How much faith should we really put into the scientific theories developed over the last 200 years that support old ages of the universe and evolution?
For me who has the benefit of knowing God, the answer is little. Don't get me wrong, I'm not disputing the scientific observations, themselves. But I do question many of the absolute conclusions that have been built, such as extrapolations into past time, simplistic models that are assumed to accurately model much more complicated phenomenon, etc.
For you who don't have the benefit of knowing God, yet, I encourage you to keep an open mind.
None. Scientific theories don't travel on faith. Faith (as philosophers use the term) is the acceptence of a proposition in the absence of verifiable evidence or logical proof.
Scientific theories are accepted because -- and only as long as -- they are: (a) consistent with all relevant observations; and (b) make verifiable predictions. The history of science indicates that even widely accepted theories are overturned if evidence is found that contradicts the theory. The best-known example is the once universally believed idea of a steady-state universe, which recently gave way to the big bang theory. Today, there are no "steady-staters" clinging to their disproved theory on faith.
So if there are good scientific reasons why a theory should be rejected, it will be. No faith is involved.