'The marketplace' is a synonymous term for the world of business and commerce and a term which describes a situation or place in which values, opinions, and ideas are put forward for debate or recognition - e.g. the society around us.   

In our Constitution we reflect on the importance of the marketplace:
"NDIC is dedicated to the nurture and inculcation of Christian faith, values and disciplines as well as their integration and expression in daily life at home and in the market place. It seeks to help those who attend its regular gatherings to discover life in its fullest potential as God intends for humanity which our Lord Jesus has also articulated (John 10:10), and to live fulfilled lives of love and service to their families and their communities."

In other words: 
Our faith can and should be expressed not only on Sunday mornings, but also during the week; in our career, politics, science and every other aspect of society. The Christian faith incorporates everything and gives purpose and meaning to our existence and life in this world, whether it is in the so called secular or spiritual realm.

Church thus becomes not only a wonderful place where people are invited to 'come and see', it also becomes a place where people are encouraged and equipped to 'go and be.' Jesus already talked about this when he said that his followers would be 'the salt and the light of the world' (Matthew 5: 13-16).

Being the 'salt and ligt of the world' facilitates social, spiritual and cultural enrichment and can bring about transformation in the marketplace.

A prominent present day researcher, sociologist Rodney Stark refers to this when he analysis the survival and growth of the early church in the first few centuries. He describes how brutal life was, but also the impact the church made:

". . . Christianity served as a revitalization movement that arose in response to the misery, chaos, fear, and brutality of life in the urban Greco-Roman world. . . . Christianity revitalized life in Greco-Roman cities by providing new norms and new kinds of social relationships able to cope with many urgent problems:

To cities filled with the homeless and impoverished, Christianity offered charity as well as hope.
To cities filled with newcomers and strangers, Christianity offered an immediate basis for attachment.
To cities filled with orphans and widows, Christianity provided a new and expanded sense of family.
To cities torn by violent ethnic strife, Christianity offered a new basis for social solidarity.

And to cities faced with epidemics, fire, and earthquakes, Christianity offered effective nursing services. . . . For what they brought was not simply an urban movement, but a new culture capable of making life in Greco-Roman cities more tolerable."

Rodney Stark, The Rise of Christianity, Princeton University Press, 1996, page 161.