What Paul is saying here is that the Christian runs in his lane and he keeps to it. We will not glory in, boast of, or seek after or take credit for things that are outside our lane.
You get this today. There are churches springing up, they may be well intended. They use a name; they say we are a missional church but they water down the Christian faith a good deal. Maybe they only have one Sunday service, but then they also have a few little Bible studies, sometimes held in pubs and bars and congenial places, and they are all about entertaining and eating, and they want all the worldly pop and the modern things. They want to have a good time. They want to water down the faith, make it easy, get youngsters in. They are running out of lane. It is not according to the rules of God – preaching the Word, prayer meetings, looking to God to work in hearts, reaching out to people according to the methods of the New Testament. They may be Christians, some of them, but they claim to have devised something better, something different. But the Christian’s task is to obey God, and do things his way, and run in the lane that God has appointed.
This verse sounds complex but it is actually a very simple illustration. The King James translators did not want to interpret the passage, but there was a dispute in their time about what the verse meant, so they translated it as neutrally as they could and it actually makes it difficult for us to understand. Some people said it meant this: we will not boast of things that are outside our territory, referring to the allotment of territory to the Israelite tribes of old which they were given to settle in. It is as though Paul is saying, ‘We do not do things that are outside our allotted territory.’ But the most traditional interpretation says this is an illustration based on the Corinthian Games more famous in their day than the Olympic Games. In these games, the runners ran in lanes, and the lanes were called measures, coming from the word for reed, used to set the width of a lane.