Do Not Quarrel Over Opinions

Paul has just said that we are not to live like the nations around us. The night is far gone; the day is at hand. So there is no place in the Christian life for indulging the flesh.
Paul recognizes that there are matters where Christians may disagree. There are things that are adiaphora (indifferent).
And Paul says that regarding such things, "As for the one who is weak in faith, welcome him, but not to quarrel over opinions."
So as you welcome those who are weak in faith, you who are strong should bear with the weak.