A perfect picture of salvation offered by grace through faith is found in the story of Jesus’ encounter with the woman caught in the act of adultery. Jesus said to her, “Neither do I condemn you [that is grace, because she deserved to be condemned]; go your way; from now on sin no more” (John 8:11, emphasis added). When she deserved to die, Jesus let her go free. He sent her away, however, with a warning: From now on sin no more. This is exactly what Jesus is saying to every sinner in the world—”I’m not condemning you now. You deserve to die and be condemned forever in hell, but I’m showing you grace. My grace, however, is only temporary, so repent. Stop sinning now, before My grace ends and you find yourself standing before My judgment seat as a guilty sinner.”
Let us imagine that adulterous woman repented as Jesus instructed her. If she did, she was saved by grace through faith. She was saved by grace because she could never have been saved without God’s grace, being a sinner. She could never rightly say that she earned her salvation by her works. And she was saved throughfaith because she believed in Jesus and thus believed what He said to her, heeding His warning, and turned from her sin before it was too late. Anyone who has genuine faith in Jesus will repent, because Jesus warned that unless people repent, they will perish (see Luke 13:3). Jesus also solemnly declared that only those who do the will of the Father will enter heaven (Matt. 7:21). If one believes in Jesus, one will believe and heed His warnings.
But let us imagine that the adulterous woman didn’t repent of her sin. She kept on sinning and then died and stood at Jesus’ judgment seat. Imagine her saying to Jesus, “Oh Jesus! It is so good to see You! I remember how You didn’t condemn me for my sin when I was brought before You on the earth. Surely You are still just as gracious. You didn’t condemn me then, so surely You won’t condemn me now!”
What do you think? Would Jesus welcome her into heaven? The answer is obvious. Paul warned, “Do not be deceived; neither fornicators…nor adulterers…shall inherit the kingdom of God” (1 Cor. 6:9-10).
All of this is to say that Jesus’ requirements for discipleship are nothing more than a requirement for genuine faith in Him, what amounts to saving faith. And everyone who has saving faith has been saved by grace through faith. There are no biblical grounds for the claim that, because salvation is by grace, Jesus’ requirements for discipleship are incompatible with His requirements for salvation. Discipleship is not an optional step for heaven-bound believers; rather, discipleship is the evidence of genuine saving faith.
This being so, to be successful in God’s eyes, a minister should begin rightly the process of disciple-making by preaching the true gospel, calling people to an obedient faith. When ministers promote the false doctrine that discipleship is an optional step of commitment for heaven-bound believers, they are working against Christ’s commandment to make disciples and are proclaiming a false grace and false gospel. Only Christ’s true disciples possess saving faith and are going to heaven, just as Jesus promised: “Not everyone who says to Me, ‘Lord, Lord,’ will enter the kingdom of heaven; but he who does the will of My Father who is in heaven” (Matt. 7:21).
 It is also helpful to keep in mind that the reason Paul often affirmed that salvation is by grace and not works is because he was constantly fighting the true legalists of his day. Paul was not trying to correct people who taught that holiness is essential for heaven, because he himself believed and often affirmed that fact. Rather, he wrote to correct Jews who, having no concept of God’s grace in salvation, did not see any reason for Jesus to have died. Many did not believe that Gentiles could ever be saved because they had no concept of God’s grace making salvation possible. Some thought that circumcision, physical lineage, or keeping the Law (which they did not do anyway) earned one’s salvation, thus nullifying God’s grace and the need for Christ to have died.