Mentoring and Church Planting=Molding and Strengthening
Mentoring and church-planting are vital to the work of missions. Mentoring is molding by modeling. Authentic, mature, practical Christianity is the essence of mentoring-- where truth is caught, instead of taught. This molding process is actually an integral part of equipping the saints for the work of the ministry, Paul instructed. And, Be (ing) an example of the believers is necessary for the teacher, in order to impact the students and inspire them to lead.
The Apostle Paul planted churches, strengthened the local church body, trained the nationals, turned the work over to them, and moved on. And so, if our missionaries would be imitators of the Biblical pattern, they must do the same.
Church leaders are referred to as shepherds in the NT. Shepherding means teaching, nurturing, feeding, sharing resources, facilitating, and building a strong church. All through the NT, the local church is the main vehicle for carrying out the Great Commission. In, through, and coming out of the local church is missions, the only way to fulfill Jesus' Acts 1:8 command to go to Jerusalam, Judea, Samaria and the uttermost parts.
Without sending-churches, missionaries are operating outside of God's missions template. And they have no Biblical authority watching over them. Their primary accountability is to their sending-church, which is also their main source of prayers, encouragement, blessing, partnership, and involvement.
Without strong local churches being established among the nations, the nationals will not be able to fulfill their obligation to obey the Great Commission according to God's plan. Strong national churches end up being the next level of sending-churches!