In addition Faith, there is a place where we can actually observe the past in pretty great detail and over a range of millions and billions of years and that is through astronomy. We can see the same processes that are happening today happening at different time periods across a span of billions of years.
Remember, changes do leave evidence and that evidence is also available over a somewhat shorter time span of only a few billion years here on the Earth and you have been presented with that evidence numerous times here at EvC. One great example is the Oklo reactor. We can see the waste products and compare those to what is produced in modern reactors. Another example is air trapped in bubbles in ice cores. We can actually test that are to compare it with the air today. We have fossilized rain drops that we can compare to the pattern made by rain drops today.
The (prehistoric) past is NOT unwitnessed since all change leaves evidence. And those who have eyes can see.