One person considers one day more sacred than another; another considers every day alike. (Romans 14:5)
I suppose the situation now is that some people use this as a proof text against the commandments of God to keep the Sabbath day holy, which, since the Lord Jesus has risen from the dead, has been on the first day of the week, namely Sunday. The temptation may be to say, “Look, this is Paul saying that it doesn’t really matter whether you keep the Lord’s Day holy or not.”
But if we compare this text to other passages, what we see is that, actually, we are expected to keep the first day holy, that isn’t a disputable matter. We go to creation, we go to the Ten Commandments and see that we were designed to keep one day holy, and even though the day has changed in this New Testament age, it does not mean that the idea of keeping one day holy has changed.
We also see in the book of Acts that, from very early on, the church began to gather on the first day of the week to break bread. We see that in Paul’s instructions to the church in Corinth about when to set aside offerings in worship—it’s on the first day of the week. The apostle John, in Revelation, speaks of the Lord’s Day when he was in the Spirit too.
So, we are to look for a day which is the Lord’s Day, which is our practice in AP.
