I’m not really “into” football. I can enjoy watching the occasional match, or highlights, and see the skill and planning. But I don’t support one team, and somehow it seems that it’s not a sport where you can just enjoy watching, you have to be a supporter.
I wonder if Paul would have used that metaphor when in Romans 6:12-23 he argues with those who can’t understand grace. “What!” they say, “If we are saved by grace through faith, there is no point in being good at all!”. Paul is horrified. The point of the new life is that it is “in Christ”. Just as we are set free by his death, so our freedom is to live his new life. That new life is not about earning approval by being good and following the rules, but it is certainly about sharing his love, and using the gifts of the Spirit in the service of God’s Kingdom wherever we are.
The comparison Paul does choose in these verses is slavery. If, having been a slave, you are set free – then life can go different ways. You can fall back into slavery, because you run into debt and are sold to make a payment. Or you can make the most of your freedom.
But it is wider than that. Think of walking up a mountain ridge. On either side, the ground slopes down, gently at first. You can go either way. (One way represents “the way of righteousness, leading to holiness”, the other impurity leading to “ever-increasing wickedness”). Once you start down, left or right, it is easier to go on in that direction, and takes more effort to move back. The further you go, the more you lose sight of the other side. It is just the way things are. Christian freedom can be diluted by the pursuit of pleasure, until the individual becomes ensnared, and all sight of a life of holy love and service is lost. But a life which looks to what God is doing becomes ever more interested and involved in that.
Paul knows that we are not simple characters, and will go on to talk about that. But every life can be searched for an aim, a big ambition. Here he reminds his readers that they all have something to be ashamed of in their former lives. Now that they have been freed by the love of God, so they should use these newly released lives to search out and share all the goodness available in this Saviour.