I want you to think about the fact that living things are irreducibly complex. That might sound complicated, but it just means that a living thing is an entire system of interacting parts working together, and if even one of those interacting parts is not present from the beginning, the living thing would not be able to survive. Think about it, let's imagine that a fish evolves lungs through evolution. What happens to it...does it keep changing and eventually become a frog? Nope, it just drowns. A frog needs every organ in his body to survive - it is irreducibly complex, so it could not have slowly changed from a fish into a frog. When sharing this with unbelievers, just remember this short story of a fish evolving lungs and drowning. Living things are irreducibly complex.