You heard it from me before but here’s a wiser man than me arguing for the importance of the workplace in evangelism:
The front lines of evangelism in any moment of history will be, first, the family and then the workplace. For most adult believers (unless our immediate family members are non-Christians), the context in which we are most likely to meet unbelievers is our place of employment. There day after day, for eight or nine hours or even longer, we will be working under, over, or alongside people who do not know Christ…This was as true in the New Testament period as it is now.
God wants people to be farmers, schoolteachers, nurses, janitors, lawyers, homemakers, doctors, tradesmen, accountants, etc. He delights in raising up people to serve Him in every job. We are to regard very kind of work as a sacred calling, and we are to teach all God’s people to work as those who are working for the Lord. As we do this spiritual and blessed daily labor, we are given the added blessing and possibility of being living testimonies to the power of of the Gospel by the way we work…For this we were created, for this we have been redeemed, that our lives might be a constant praise to Him in all we do.
Jerram Barrs, The Heart of Evangelism, pages 59 & 62