Not that one is necessarily better than the other, but clarifying can clear up and prevent frustration. If you have a job, that's fine. But if you have a ministry and approach it like a job, you do a disservice to yourself and the ministry.
A job is at your choice; a ministry is at Christ's call.
In a job you expect to receive; in a ministry you expect to give.
In a job you give something to get something; in a ministry you return something that has already been given to you.
A job depends on your abilities; a ministry depends on your availability to God.
A job done well brings you praise; a ministry done well brings honor to Christ.
~James N. Spurgeon