Discipline is an inseparable part of the good life. That statement sounds counterintuitive, but I assure you that it is wholly true. Almost nothing in life that is good comes without some kind of discipline. If you want to be good at your job, you have to discipline yourself to learn, perform, show up on time, and be nice to your co-workers and your company’s customers. If you don’t, you will, at worst, be fired, and at best you won’t advance. If you want to be wealthy, you will have to discipline yourself to work hard, to save money, and to make sound financial decisions. If you don’t, you likely will be poor, in debt, or both. If you want a good marriage, you will have to discipline yourself to prioritize the marriage relationship and not your own desires and pleasures. If you don’t, you will either be divorced, or miserable. If you want to have good health, you will have to discipline yourself to be attentive to what goes into your mouth, and your mind. You also will have to discipline yourself to work your body regularly. If you don’t own those behaviors, you likely will develop diseases of affluence.
Spirituality is no different. If you want to grow spiritually, you will have to prioritize your relationship with Jesus, and keep your mind focused on those things that please him (Colossians 3:1-4). If you don’t, then your spiritual walk will be hobbled by things that displease him (Colossians 3:5). In fact, Paul uses a very strong argument in Colossians 3:5. He says that covetousness, which some might think of as the least of the sins in that verse, is idolatry. He doesn’t say that it is like idolatry. He says that it isidolatry. He likely makes this argument because things like covetousness, sexual immorality, evil desire — or really any sin — have a way of capturing your devotion and stealing it from God. They cause you to prioritize selfishness. They rob you of selflessness. And they put your mind in an earthly state. They put tension between you and God. Although God will discipline those he loves, it isn’t as much a tension on God’s part as it is yours. If you are truly saved, there is now no more condemnation as far as God is concerned (Romans 8:1). But having that earthly state of mind deadens your desire to be with God, and makes it difficult for you to serve him until you have laid it at his feet and submitted your will to his. Therefore, Paul argues that sin is idolatry. It gets your worship instead of God. Paul’s prescription for that ill is a strong one. He says to put to death those things in you that are earthly.