Basic Idea: Discipling other Christians involves us in imaging God’s transcendent posture and his immanent posture toward his people. On the one hand, discipling typically occurs in the context of friendship—two individuals who have affectionately drawn near to one another for the purposes of enjoyment and care. This is the immanent posture. On the other hand, discipling is a friendship with a Christward direction. The goal of the enjoyment and care is to help the other person look more like Jesus. This is the transcendent posture.
Friendship: Think about what friendship involves. Our friends are the ones we imitate and follow. We adopt their language and life patterns. We tend to spend money where they spend money. We value what they value. We raise our children like they raise their children. We pray like they pray. We trust their counsel and heed their rebukes more easily than someone who is not a friend. There’s a reason that Paul says, “Bad company ruins good morals” (1 Cor. 15:33; cf. Deut. 13:6). It’s because our friends play a large role in forming who we become as we imitate one another (see James 4:4).
The intimacy and trust afforded by friendship (immanence) makes it a perfect vehicle for instruction and teaching (transcendence).
This is why there is no better friendship a person could have then the friendship of the Lord, a friendship which is given to those who keep his covenant and do his commands (Ps. 25:14; John 15:14). To say he is our friend is to say that we imitate him. To be a friend, on the other hand, is to give, just as God gives. God gives to those whom he befriends, just as Christ has befriended us through his sacrifice (John 15:13, 15). Likewise, we should befriend the members of our church by giving ourselves to them.
Discipleship: What is discipleship? Again, it’s friendship with a Christward direction or purpose—the purpose of seeing another conformed increasingly to the image of Christ as one or both give in order for the other to receive. Indeed, Christian friendships take humility, because it requires humility to both give and receive. 
Sometimes people laugh at how particular phrases and mannerisms become contagious and overused within a group of friends or a church community. But that’s exactly how discipleship works among imaging creatures. We watch and mimic, hopefully in the right direction. “Be imitators of me, as I am of Christ,” Paul said to the Corinthians twice in one letter (1Cor. 11:1; 4:16; also 2 Thes. 3:7, 9). The author of the Hebrews likewise told his readers to imitate the faith of their leaders (Heb. 13:7). And John told the church he was writing to imitate what is good, not evil (3 John 11).
Church: As God gives humility to churches, those churches should be increasingly characterized by such discipleship friendships: young men befriending other young men for the sake of encouraging one another in the faith; young women doing the same with other young women; older men befriending one another and younger men; and so forth.
Christian friends are surely valuable inside or outside the same local church. But friends within a local church will be formed by the same ministry of the Word, giving them the opportunity to extend that ministry more carefully into one another’s lives throughout the week. Friendships are a God given vehicle through which the church’s ministry of the Word travels.
Practical take aways:
1. Pastors have busy schedules, and frankly they cannot afford to become good friends with everyone whom they disciple. Still, we can generally expect that the discipling relationships which occur in the context of a friendship will have the highest impact. In other words, the amount of time I spend drawing near to a brother (immanence) will directly affect how far I can draw that brother toward Christ (transcendence)—all things being equal.
2. Drawing near to a younger brother in the faith doesn’t mean telling him everything about my life. Questions of his maturity and trustworthiness will help to answer how much I can wisely tell him about my life to assist him in the path of discipleship.
3. At the same time, I need to make sure it’s not my own pharisaical aspirations of looking impressive to the younger man which keep me from drawing near and being transparent.
4. After all, at the heart of what we want to teach younger Christians is the glory of the gospel and the pattern of a gospel life. If the younger Christians around me never see me demonstrate confession, contrition, and repentance, how can I expect them to learn it? 
(Paragraphs 2, 4, and 5 to 8 have been adapted from The Church and the Surprising Offense of God’s Love: Reintroducing the Doctrines of Church Membership and Discipline—coming from Crossway Jan 2010). Next post:  Transcendence and Immanence in Evangelism