Final answer:
St. Paul called Luke 'the beloved physician' and he is known as one of the evangelists who authored the Gospels, significantly contributing to the spread of Christianity.
Step-by-step explanation:
In the New Testament, St. Paul referred to Luke as "the beloved physician" and recognized him as a fellow worker in the spreading of the Christian message. Luke was an evangelist, one of the four authors of the Gospels, and his work reflects a detailed account of the life and teachings of Jesus.
The relationship between Paul and Luke is an important aspect of early Christian history, as they both contributed significantly to the spread of Christianity through their teachings and written works.