For many people, ever since Thomas H. Huxley demolished Bishop Samuel Wilberforce in a public debate at Oxford University, "the truth" has been Darwin's general account of evolutionary forces gradually creating all forms of life on earth.
As the scientists say, life on Earth began millions of years ago with some chemicals in a warm puddle - something they haven't been able to recreate under perfect laboratory conditions, despite many attempts.
If life - and human life - is just a bunch of chemicals arranged a certain way, then why haven't the most brilliant scientists on Earth managed to replicate this "accident" yet? As it turns out, the case for evolution is not nearly as strong as the scientists claim.
The concept of entropy, developed hundreds of years ago by scientists and engineers, can be understood as a measure of orderliness or randomness in a system. Something with low entropy is ordered and not random, whereas something with high entropy is very random and not ordered at all.
If you haven't noticed, everything we build breaks down eventually, becoming more random over time. This is captured in the Second Law of Thermodynamics, which generally states that everything in the universe will become more random whenever the statistics allow for it. This means that pieces of machinery will break off over time, and things will crumble into dust.
But hold on a second... what about life? Although we die eventually, during our lifetimes we grow and become more complex, not more random. Plus, our bodies maintain their shape and size, generally - we don't wake up one morning with half of our arm turned to dust.
This is actually a major problem for evolutionary theorists, as they have to acknowledge that life is "neg-entropic". What this means is that life actually resists entropy, and, as the mathematics show, it does so as fast as possible. However, in the process, it consumes energy, creating more total entropy in the system.
The best that scientists can do is say that Earth, and specifically that dirty puddle that was really warm from the Sun, was a "breakthrough point" that allowed life to begin and create more entropy in the total system. Because we haven't found life anywhere else we've looked in the universe, this means that their "entropy" is a universe-wide force that makes "decisions" down to a dirty little puddle... sounds a lot like theism!
Although this sounds unbelievable, people have calculated, based on the probabilities of different molecules forming, that the time it would take for life to even start makes the scientist's evolutionary model impossible.
No matter what scientists say, the chains of chemicals that had to "accidentally" come together to form even the most basic elements of life are so complex that it is mathematically impossible for life to have formed in a dirty puddle.