The most repeated argument by a creationist trying to refute evolution is hands down the overused phrase "there are no transitional fossils, show them to me." Creationists seem to believe that there is some heavy lack of transitional fossils to support evolution theory and therefore, god created us. In reality, as you can see from the picture above, there are plenty transitional fossils, in that picture, A is a modern chimp, and H is a modern human, all with their respective ancestors, showing a smooth transition, isn't that evidence enough?.
Creationist argue that those fossils are just examples of "micro evolution" that is, the evolution of a certain form of species to the same species with several variations, they claim that there is no evidence for "macro evolution" the evolution from say a fish to a lizard, one specie to another. The truth is, there are a lot of those fossils, specially for the whale and the ones that show a form of dog that eventually turned into the modern horse. Even if there wasn't any fossil evidence at all, we have a thing called DNA testing that literally shows a big family tree between animals and all forms of life.
haters gonna hate
The problem is, creationists don't settle for that, what they want is the remains of a blob of slime with human eyes on it. or a fish with bear paws, maybe even a snake with legs, you know, just like the bible teaches us. They will never accept evolution as a fact until they get their ridiculous request, simply because they don't understand it, its funny how most of us atheist know and have studied the bible or the qu'ran, but yet, religious apologists seem to only have the slightest idea of what science is.
On my own personal experience, this intolerance and close mindedness is exemplified by a girlfriend i had a few years ago, she knew i was an atheist, but she absolutely hated it whenever i would mention something about evolution, or rationally dismissing a certain belief she had, it got to the point that she actually told me she didn't want to have any kind of religious discussion with me, and that i wasn't allowed to even give an input on any religious conversation, that meant she could absolutely tell me everything that happened to her in church, or in spiritual retirements, congregations, but, i wasn't allowed to give my opinion on the matter because that would upset her, she would cry at the idea that there was no god, and after death she would simply stop existing, some people can't cope with that fact.
Again, creationists aren't interested in explaining anything, they want to believe their silly things and shove them down everyone else's throat, no need for investigation, no need for facts, only faith, they want faith in schools, they want to teach our kids that just believing in something is quite alright, don't even worry about looking for anything that contradicts your thoughts or beliefs. Ever since i became an atheist, i love looking for counter evidence of what i now know, i'm always visiting religious sites, checking out creationist videos on youtube, basically anything i can to inform myself better on what other people believe.
Creationists, or any kind of religious person can't do this, if they spend more than a few hours studying evolution, or what atheists know or simply things that go against their beliefs, just like the example i gave, they might leave at least with a few doubts on their mind and most likely lie to themselves about the evidence just to keep their unfounded ideas. Doubt is probably one of the biggest reasons why the church makes them go take a weekly lecture or reinforcement of faith, a church is not a place where you can have rational discussions, unlike classrooms, you can't just stick your hand up and present a different idea from what the speaker is saying to have a small discussion or debate, in a church, something like that would definitely get you kicked out.