The so-called “5-day workweek system" has become an overwhelming trend in our days. How should we deal with this issue? The churches in Korea have tried to respond to the situation in many different ways. Unfortunately, however, most of the Korean churches’ educational programmes that have been developed to deal with the “5-day workweek system" usually lean toward one-sided methods and programs lacking solid theological basis. They have focused mainly on fragmentary theological themes like “keeping Sunday holy" or “labor and rest". However, neither the program-oriented approach nor the one based on the fragmentary theological themes is sufficient. Rather, it would be necessary to make sure that the educational ministry should be grounded on a more comprehensive theological foundation. Because in Christian education, ‘Christianity" and ‘education" are inseparable in nature. Broadly speaking, it is believed that ‘Christianity’ means the theological basis of the Christian education, while education concerns the practical aspects of it. As such, from a Christian educational viewpoint, it is essential to design the educational mi nistry on the basis of a more comprehensive theological prospective. Then, what should be the theological ground in our educational ministry to tackle the challenges of the “5-day workweek system?" I would heartily recommend “holiness". The reasons are as follows: First, the word “holiness" first appeared in the Scriptures together with the Sabbath. The concept is vital to resolving the problem of “keeping Sunday holy". Second, taken as a whole, the Bible shows that the Church is called the Holy Church and the Christians the holy people. It gives the fundamental identity to the Church and Christians. Finally, the word ‘holiness" means, on the one hand, separation from the world on the other hand, it means a certain group of people being declared to be God"s own. It teaches how to live for all Christians in a changing world like ours. Moltmann explicitly mentioned holiness three times in his major works. First, he referred to the holiness of the Church which is one of “the marks of the church" in the last part of his The Church in the Power of the Spirit. Second, he also mentioned the sanctification of creation in the closing part of his God in Creation. Finally, we can discover ‘the holy life" in his The Spirit of Life. In other words, Moltmann described holiness in three different contexts the distinctive character of Church, the Sabbath as a sanctification of time, and sanctification of life. I propose that the educational ministry of the church be based on these themes to overcome the challenges brought on by the socio-cultural changes arising from the ‘5-day workweek system". The holy Church, holy time, and holy life should become the theological foundation for establishing the educational ministry of the church to deal with the ‘5-day workweek system".