Answer:
Career mostly likely meaning job as it it used in the sentence.
Answer: It basically means something can look beautiful on the outside but on the Inside, it can be mean and cold. Just like how people are.
Explanation:
In the sestet from Sonnet XIX by John Milton,the idea of service to God interpreted is that God asks only for faith, devotion, or acceptance rather than asking for demand of work. It is that the God just wants faith and devotion of people to him rather than any kind of works.