When we meet someone for the first time and have a conversation. A natural question is: what do you do for a living? In many ways your job defines you, it is your occupation.
In 2 Timothy 2, Paul calls Timothy to take on ministry roles and jobs such as: soldier, worker, servant of the Lord. What he is to be, defines not only his job, but his life, direction and character. The same sorts of roles that we are to take, as we see a lifetime of Christian discipleship before us. We are to have these Gospel occupations of: soldiers, workers and servants.
The Gospel is to be our occupation, as we are to be strong in the grace of Christ Jesus.