The word "living" is an action word. For a genuine disciple, growth will occur. It's simply a fact of life.
The world is filled with people who claim to be "saved," but who don't show it by their lives. The Bible describes such people as "fakes" and "hypocrites," and warns us that all such people will perish (unless they repent - change the way they think and act). This may be an unpleasant topic (especially if it condemns us or people we love dearly), but it is a strong emphasis in the words of Jesus, as well as in the words of the apostles.
A "disciple" is, by definition, a learner and follower - and if a person is unwilling to follow Jesus, then he isn't following him! How could it be any clearer?
This doesn't mean the disciple will never sin or have "setbacks." But sin will not be his lifestyle. We, Jesus' followers, will struggle all our lives, but we will not choose to live a life of sin. (This refers to "sin" as God defines it, and includes both what we do and what we fail to do - James 4:17. See also the section about Sin.
This section focuses on our responsibility, as disciples, to fight against sin and to overcome it. But there is another focus in the Bible, which is mentioned in several articles (located in other places on this website). This other focus is on the way that God works in us, to accomplish these things. We have the power to overcome, because he gave us both the power and the desire to use that power. It is because of this, that we have hope - for we could never survive on our own. It is also because of this, that we have no excuse for being unwilling to live the life of a disciple, if we claim we are one.
It will happen, because God will complete in us what he has begun. But we also need to be willing to make it happen. Many times in Scripture, these two concepts parallel each other. How? We don't need to "worry" about how they fit together; we just need to do our part (realizing that our success is to God's credit) and let God "worry" about the rest!
We need to interact with other followers of Jesus. All who are genuine followers of Jesus (disciples) belong to the same family - and Scripture doesn't treat this as mere figurative symbolism. A change has begun, and will be completed at the resurrection. In the meantime, God commands us to acknowledge each other's presence, and to interact with each other. He also tells us how we are to do so - which is quite different from the frivolous way many people of the world (and many "church goers") interact with others.
If a person ever told you something like, "Turn to Jesus, and your problems will go away," he lied to you! Sure, there are some trials and difficulties we won't have, because we don't choose the path of sin that leads to them. But other trials are just a "fact of life" for everyone. In addition, when we turn to Jesus, we now stand opposed to the powers of evil; and they will try to bring additional trials into our lives - trials that the world won't necessarily have. (Of course, God will use those trials to accomplish good in our lives - Romans 8:28.)
Life in Christ is wonderful, but it isn't easy. Sin and temptation exist, both within us and surrounding us. We are to take this matter seriously and not "play" with sin - for doing so is not an option for a follower of Jesus.
The Bible says...
Dear friends, you have always obeyed, not only when I was present, but even more so when I was away. So, as you have done in the past, continue to do now: Work out your salvation with fear and trembling. After all, it is God who is working in you, not only enabling you to obey, but also enabling you to have the desire to obey! (Philippians 2:12-13)