Introduction
How help can we help brothers and sisters who no longer lives for Christ? How should we consider them? How can we restore them? Two aspects: theological, practical. What does Bible say about Christians who fall away? Practically, how can we make a difference in their lives?
Grid for understanding the problem: Unbelieving unbelievers. Believing unbelievers. Unbelieving believers. Believing believers.

I. Not everyone who claims to be a Christian is.
John Piper, Desiring God: "We are surrounded by unconverted people who think they do believe in Jesus. Drunks on the street say they believe. Unmarried couples sleeping together say they believe. Elderly people who haven't sought worship or fellowship for 40 years say they believe. All kinds of lukewarm, world-loving church attenders say they believe. The world abounds with millions of unconverted people who say they believe in Jesus." Piper is describing unbelieving believers.
In John 6:54ff, Jesus causes a stir, disciples withdraw, follow no more. Some profess to believe, but do not. John 6:64, JC says some do not believe although they profess to follow.
A similar problem is reflected in John 12:42.
This problem takes several modern forms. People who think they are saved but have not truly believed. May have faith, but that faith is deficient or defective.

~~People who believe "in" JC, only that he existed, but that does not change their lives.
~~People who trust Christ, but also trust their own good works for salvation.
~~People who profess to trust Christ but whose lives have never mirrored his life in loving, obedient baptism in response to his claims.
~~People who profess to follow Christ, but do not live changed lives.

II. That a person sins is not a denial of one's Christianity.
2 Corinthians 13:5, test self whether be in faith. Need clear understanding of gospel. John MacArthur, The Gospel According to Jesus, "The contemporary church often fails to present the gospel clearly enough for the non-elect to reject it." Do not want to garble gospel with issues not an integral part of God's salvation offer, but neither do we want a watered-down gospel that fails to demand obedience.
Christ challenges his disciples about commitment levels, Mark 10:17-23; Luke 9:57-62. Yet he presented discipleship in gentle, encouraging terms, Matt. 11:28-30.
Live in day of cheap grace, but term is not defined. Listen to S. Lewis Johnson, "Christianity Today," (9/22/89): "The glory of the gospel of grace and limited response do not seem compatible, but solution is not to be found in inducing shallow professions that do not last by questionable methods of 'decisonal evangelism'..." Goes on to argue against stringent demands that have no biblical support. Great need to preach an accurate gospel.

The glory of the gospel of grace demands unlimited human response.
The glory of the gospel of grace focuses and recognizes the limitations of any human response.
The glory of the gospel of grace points exclusively to God's initiative and God's saving power.
The glory of the gospel of grace depends not at all upon human initiative or meritorious action.
The glory of the gospel of grace motivates human response and such human response must never be denied as sufficient evidence of the presence of grace.

III. Christians must deal with personal, individual doubts.
Need clear statement of how God sees sinning Christian. 1 John 1:5-10. Sinful, admitting sin, yet sufficiently covered by Christ's blood because of one's walk in the light.
Can a Christian become apostate? Yes. Demas, Simon the Sorcerer. Departed from or rebelled against truth. Gal. 5:4. Just because some falsely entered the church in the first century, Jude and 1 John 2, does not mean that all were insincere. Sincere people obviously fell away. Hebrews 6:4-6. To renew means to bring to state formerly held.
Yet the mere presence of doubt does not deny faith. One cannot really believe what one has not doubted.

IV. Christians must help rstore wayward brothers and sisters.
People drift from close, personal relationships with God and God's people. Who will bring them back? and how? Will God miraculously swoop down? Surely not. We must restore such: Gal. 6:1.
Listen to words from Hannah Whitall Smith in 1875: "The standard of practical holy living has been so low among Christians that very often the person who tries to practice spiritual disciplines in everyday life is looked upon with disapproval by many in the church. For the most part, followers of JC are satisfied with a life so conformed to the world, and so like it in almost every response, that to a casual observer there is no difference between the Christian and the pagan."
Believers have a responsibility to help other brothers and sisters. Gal. 6:1, written not just to church leaders, also 1 Cor. 5. Caught indicates ensnared or overpowered by sin, unlikely to escape without help. Spiritual means walking by the spirit. Restore has idea or returning to original state, mending net or resetting broken bone. While process may be painful, is process of restoration rather than punishment. Must be done in love, gentleness, Eph. 4:15.
What should we say? No formula given, but may remind brothers and sisters of Romans 12:1. We belong to God, purchased with price, redeemed. Christians who are sinning consciously are usually disappointed or disillusioned with God, the Christian life, fellow believers, or all three. These believers have usually not forgotten what God did for them at the cross, but they are wondering why things are so apparently wrong or bad now. In order to restore these believers, encouragement will be necessary. Heb. 3:13.
When we encounter a fellow believer who is ensnared in sin, but has little interest or inclination to escape because of disappointment, disillusionment, or denial, we must encourage such a one. Takes time, relationship. Probe gently, kindly, listen intently. People who are away from God often do not want to admit it, or cannot verbalize their problems. Know something is wrong, but cannot figure it out, so blame God.
We must help pinpoint problems and lead sinning Christians back to God's word. God chastens, Heb. 12. We are to help the weak, 1 Thess. 5:14. Often spiritually weak Christians want to do what is right but lack the discipline to follow through. Often such are new Christians, or those who failed to grow. May be that sinful past causes continual struggle with certain sins. Occasional encouragement or exhortation alone will not turn the lives of these believers around. Need constant supervision and support to turn from sin. Need accountability with fellow Christians.

Conclusion
God wants to revitalize our lives. Christians sin, but we have an advocate with God the Father, Jesus Christ, 1 John 2:1. JC provides a way back so that we may truly be disciples. Such does not occur overnight. Such is lifelong process of learning and growing. Yet if we will pursue the things of God, lives will be changed. And as our lives change, we will change the lives of others.