Ministry (diakonia) is service. Who determines what is service? The one being served. God calls, we serve. ANYTHING done in service to God is ministry. Here is how I see it.
Human Vocation – In Genesis 1 and 2, we find a call to exercise dominion, a call that is reiterated in various ways throughout Scripture, to function as God’s stewards, to bring the earth to its fullness. That includes our individual initiatives as well the social structures we create to accomplish this mission.
Christian Vocation – We are baptized into the Kingdom of God. We are called at baptism to carry on the redemptive work Christ initiated with his earthly ministry: telling the good news, caring for poor, healing the sick, seeking justice, generally pursuing shalom, inviting others into the Kingdom.
Personal Vocation – Human vocation and Christian vocation shaped by my particular set of abilities, experiences, and passion. (Distinct from an occupation, which I’d say is a particular application of personal vocation to our particular context for economic survival. Personal vocation is more encompassing than an occupation.)
The church tends to collapse “ministry” into activities that correspond directly with Christian vocation. Some will say they left the corporate world to enter “full-time ministry.” Acts of preaching and evangelism (Evangelical world) and acts of social justice (Mainline world) are seen as “ministry.” Daily life is merely a platform for executing acts of “ministry” as directed by ecclesial professionals. Daily work unrelated to these ends has no intrinsic value (though they may have a derivative value in providing incomes that generate offerings that allow for the continuation of “ministry.”)
To be clear here, we ARE all called to redemptive works of evangelism and justice. But the work in our daily lives is ministry every bit as much as redemptive work is. I’m rejecting a dichotomy in favor of an inextricable intertwining. Ministry is ANY work done in response to God’s call.