Uniformitarianism is a big word to describe the prevailing scientific philosophy of the world. It is the idea that everything in nature has proceeded in a regular and smooth fashion since the start of the Universe.
Of course, modern scientists do not accept a smooth uniformitarianism. They accept for example, a number of catastrophes and major events shaping the world we live in. But these are still considered to be part of the overall onward progress of unguided evolutionary change.
The apostle Peter refers to such people as “scoffers”. This is because they refuse to believe that God created, and prefer to believe in gradual uniform progress – as we read in 2 Peter 3:4, they say that “all things are continuing as they were from the beginning of creation”. Peter goes on to show that these scoffers are deliberately overlooking two facts. Peter says their actions are deliberate. It is not a mistake that they overlook these things. It is because, as another apostle, Paul, says “although they knew God, they did not honor him as God.” So Peter tells us that the scoffers deliberately forget that God made the world and that God flooded the world. Once we take these two events, recorded in Genesis, into account, the rest of our understanding of how God has shaped the world becomes so much clearer.