The question is "Is the present the key to past history"? People who believe in the Uniformitarian theory use this philosophical saying : "The present is the key to the past" to explain the age of the earth and the processes that shaped it. Charles Lyell, the father of Uniformitarianism, believed the same geological processes operating in history have been operating ever since rain fell upon the earth and will continue to operate as long as rain shall continue to fall. Uniformitarianism assume that God is absent, or at least relatively, uninvolved, from what occurs in nature. They are willfully ignorant and ignore the many evidences of His Creatorship and the Flood, as if He was not obviously active in and with His own Creation (2 Peter 3:3-5).
Colossians 2:8 tells us to beware of this type of philosophy. "Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ."
Lyell's so-called theoretical "key" cannot unlock the mysteries of what Earth was like before Adam disobeyed God, or why conditions exist the way they do now. We need the book of Genesis to unlock those mysteries, that is the "key" for understanding our origins.
The global cataclysmic flood waters that covered the Earth (Genesis 6-9) was the major event that shaped the Earth with the many formations we see today (Canyons, ocean trenches, major mountain ranges, volcanoes, etc.). It did not take deep time at a slow rate of process to create the Grand Canyon. The Grand Canyon was formed rapidly. The Mount St. Helens explosion gave us a small version of the Grand Canyon in a short period of time. The volcanic eruption of Washington's Mount St. Helens illustrates how sudden and drastic geological change can occur and why uniformitarian canyon-formation assumptions fail.
Because God loved His creation, He entered into it 2,000 years ago as mankind's Saviour. There is many infallible proofs of His existence : His incarnation, earthly ministry, sacrificial death and resurrection. The Lord Jesus Christ is the "key" to eternal life (Romans 6:23b). He is the "key" to the door of Heaven (John 10:7),(John 14:6). Amen!