Adam is shown conversing with God, naming some (not all) of the animals, and meeting his wife, all within the first day of his existence (If you think that’s too much for one day, see here and here). He is also expected to understand and follow the commands God gave him, one of which was to be “fruitful and multiply”, meaning both Adam and Eve were sexually mature, despite being less than 1 day old. All this points to Adam being created as a mature creation.
Korah’s rebellion, in Numbers 16, comes to mind. 250 men, some of which were Levites (Nu 16:8), joined Korah, Dathan, and Abiram in a rebellion against Moses and Aaron and were sentenced to death by God for their actions. Afterward, many others rebelled and 14,700 more people were killed by God. Presumably some of those may have also been Levites, though the text does not say.
Other instances of God killing/punishing individual or small numbers of Levites for wrong-doing include God’s prophecy to Eli that his two sons would die for their wicked ways (1Sa 2:12-36). This was fulfilled when they died when the Ark was captured by Philistines (1Sa 4:1-11). Moses and Aaron were constantly doing things that upset God, which prevented them from entering the Promised Land. Levites would also have been among the Israelites that “did what was right in their own eyes” whenever there wasn’t a judge to lead them in the ways of God, and as a result fell under numerous oppressions from foreign nations along with the rest of Israel. I’m guessing many people (including many Levites) died during those oppressions.
I have encountered no convincing argument that the genealogies are anything but accurate historical records of the people who lived at that time. Even if there are missing generations, the chronology would not be disrupted. For example, whether Enosh was Seth’s son, grandson, great-grandson, or even great-great-grandson, he was still born when Seth was 105 years old. So while there may be (but almost certainly aren’t) genealogical gaps, there are no chronological gaps, meaning they still add up to an age of the earth of just over 6,000 years.
That’s one big difference between us. I do not believe age can be measured, only inferred based on our interpretation of the evidence, an interpretation that is influenced by our – you guessed it – presuppositions. For example, we can infer the age of a person by interpreting their maturity, appearance, and other physical pieces of data, but that can only get us so far. The best way to know their age would be a birth certificate or an reliable eyewitness testimony from someone who watched them grow up.
I wasn’t referring to these geologists, so my statement that many (I did not say all) evolutionists start with the conclusion of billions of years still holds water. I can speak from personal experience. Most of the evolutionists I’ve met at college have never questioned or explored the reasons for accepting billions of years, and are mildly shocked to meet someone who believes differently.