A theory in science is supported by evidence. Some of the evidence they cite is fossil records
The fossil record is a good place to start.
Scientists have always been desperate to find "the missing link", a fossil of a transitional species between ape and human.
In the first half of the 20th century they had piltdown man. Most of the theory rested on piltdown man, supposedly discovered in 1913.
40 years later it was discovered that it was a hoax, a humans skull had been attached to an apes jaw. People were so eager to push forward their theory that they resorted to fraud.
These days we have Lucy. Their best fossil evidence for humans coming from apes. A clay sculpture created from about 40% of a skeleton.
These bones were found scattered along a hillside, so its an assumption that there from one being, they could easily be from several beings.
There were no foot bones found so it's an assumption that her feet are like humans and not like apes with a thumb.
Only small fragments of her skull was found so it's an assumption that her skull resembles a humans.
Her hip bone was modified to make it fit like a humans.
The clay sculpture has other human like features such as whites in her eyes as opposed to black eyes like an apes, yet another assumption.
If we assume that these fossils are from from one being then it is only a further assumption yo say its from a transitional species. It is most likely just from another ape.
Other supposed transitional fossils have been put forward, but again, their only assumptions.
For example, they think that birds came from repltiles. Archaeopteryx fossil is thought to be a link between them. But it could just easily be an extinct species. It's very speculative to say that it's a transitional species between reptiles and birds.
They only just look at a fossil and then make the assumption that it's some kind of transitional species when it's probably just another extinct species.
They do the same with plants. In the early 20th century someone looked at two flowers and concluded that one evolved from the other because of their similarity. They didn't know about DNA back then. Several decades later they find that one flower had twice as many chromosomes as the other making that claim highly unlikely.
You should look up all this stuff that ive mentioned
You said "i also find the resemblance between humans and chimps striking; it makes sense"
That's an assumption. Many birds look alike but it's only speculation to say that one species came from another.
We see that a horse can mate with a donkey and produce a mule, seemingly a new species, but mules are infertile and cannot maintain its species.
Humans have been breeding animals for a long time, cows, chickens and so on but never has a new species been seen coming from another.
Dogs have hundreds of mutations, we call them breeds, but a dog is still a dog, they can all still breed with eachother no matter how big or small they are despite smaller dogs choosing to breed with other smaller dogs.
Its the same with DNA. Sure they find many similarities between human and ape DNA. Thats expected considering we have many common features. But there are also key differences so it is very speculative to then assert that human came from apes because of any DNA similarities.
So the resemblance of things is not very good evidence of a species evolving from another.
The thing about theoretical science is this. They come up with an idea, a hypothesis, a theory. Then they look for evidence to support that theory. The problem is that they ignore any evidence that opposes the theory and they operate on speculation too much. And seeing that there are many atheists eager to disprove God in these fields, many of them are willing to engage in fraud or extrapolate assumptions.
This post is getting quite long and it's almost midnight here so I'll talk about, cells, single common ancestor, laboratory findings and other things next time.
But I encourage you to look into it further. Look at what people supporting intelligent design have to say and look at some debates that people from both sides have had over the years. One of my favourite believers in intelligent design is a scientist by the name of Stephen Meyer, he has many compelling arguments against the theory of evolution and has written books on it, there are plenty of youtube videos of him talking about this.