This research proposes a pastoral theological reflection on leaving in the marriage process based on the third-order pastoral theological method. It was conducted on 24 interviewees including 12 children and 12 mothers who have gone through the marriage process. The conclusion is as follows. First, leaving provides the opportunity of theological change from the first-order theology to the third-order theology to the mother and child. To this end the theology of paradox is quoted. Second, leaving transforms the mother-child relationship into fellow workers. Third, through leaving the mother and child reflect on the love of God and react to the guidance of God. Fourth, “cell-division for embodying the body of Christ”is proposed as a new metaphor for leaving.