Okay, so imagine you have a really good friend named Luke. Luke is really smart and knows a lot about a special book called the Bible. He wrote one of the books in the Bible called the Gospel of Luke. This book tells the story of a man named Jesus who did amazing things like healing sick people and teaching others how to be good.
Luke, just like any good friend, wanted to share this story with his other friends so they could learn about Jesus too. His book is really important because it helps us understand more about Jesus and what he did when he was on earth.
In addition to that, Luke was also a doctor! He knew a lot about medicine and he used his skills to help people who were sick. He even tells stories in his book about how Jesus healed sick people, and maybe he learned a thing or two from Jesus himself.
So, in short, Luke the Evangelist is a really smart guy who wrote a book in the Bible about Jesus and also helped people with his medical knowledge. He wanted to tell people about Jesus and help others, just like good friends should do.