Have nothing to do with godless myths and old wives’ tales; rather, train yourself to be godly. For physical training is of some value, but godliness has value for all things, holding promise for both the present life and the life to come.
The Bible teaches us that we are born in sin. And that therefore it is just natural to us that something is wrong, and that we are wrong ourselves. Although given the entire story of scripture, it is not naturally human, but tends toward being inhumane. Our humanity recovered in and through the one true human of creation, in whose image we’re remade in the new creation: Jesus.
It is true that when we’re older, what we are has been developed through many days, months, years, even piling into decades of choices. Amidst that there are hopefully adjustments along the way for needed change, which by the way in themselves are not snap of the finger creations. Usually it takes us awhile to slide into bad habits, and only good habits practiced awhile will get us out of them. A change of heart is always involved, so that we end up in the long run having a new desire entirely, and don’t want to do what we wanted to do before. But before we get there, we likely will have to engage ourselves in some rigorous training, which will involve disciplining ourselves to do what we are not prone to do, and to avoid what we would do, left to ourselves. The self-control which is part of the Holy Spirit’s fruit in our lives, the heart of which is love, and is actually relational (see Galatians 5) figures in prominently here.
I believe it all begins with God’s word, scripture, and with the gospel. We meditate on that, and take it to heart and life. And we make no compromises with sin. And when we do sin, we confess it, and hold on in faith to get God’s help and victory over it. And we make repentance and change of life an ongoing part of our faith, and of growing up together with others toward full maturity in Christ, and therefore full Christian maturity.
We have to be intentional about this, and remember it’s all in the context of love for God and for others. It’s not meant to be lived in a vacuum, and yet there is the aspect of it that is between ourselves and God. But it never ends there. God insists that it is also between ourselves and others. And in the context of the passage quoted above, a pastoral letter, it is about Timothy’s relationship to his congregation of believers and followers of Christ, and how he is to lead them as a pastor. He is to be an example himself, so that they not only learn from his words, but also from his life. And part of that example is the pastor’s commitment to train for godliness, to be in that process. Not having arrived in the sense of God’s work being finished, but stable in a number of ways in the change that God brings in and through Christ.