These words are the beginning of a section of teaching from Paul on how to handle sometimes sensitive areas. Areas that can have great implications on how the body of Christ works together.
They connect back to his words a couple of chapters ago, where he says that "each member belongs to all the others." (Romans 12:5). If we're all members of one body and belong to each other, then how we treat each other when it comes to disputable matters is really important.
Paul uses examples that were relevant to the people he was writing to. Eating meat versus only vegetables. Or treating one day as more sacred than another, while others don't. Paul was speaking about those things where there isn't a hard and fast rule about them for Christians.
He didn't try to create rules for them where there wasn't one. Instead, he encouraged them to consider how they were treating one another in these situations. If they were truly living as members of one body and as if they belonged to one another, then there would be consideration for each other in these areas.
In Romans 14:13-15, he says:
"Therefore, let us stop passing judgement on one another. Instead, make up your mind not to put any stumbling block or obstacle in the way of a brother or sister. I am convinced, being fully persuaded in the Lord Jesus, that nothing is unclean in itself. But if anyone regards something as unclean, then for that person it is unclean. If your brother or sister is distressed because of what you eat, you are no longer acting in love."
It's not love for a brother or sister in Christ if we're causing them to stumble because of something we do around them. If we're really living as if we belong to one another as members of the body of Christ, then we're not going to do things we know cause a problem for another member of the body.
No where does it say that we don't have the freedom to do these things. We're still free in Christ. But, our actions and choices impact those around us and if we really love them, we're not going to intentionally cause a problem for them.
It's not worth it. Our freedom should not be coming at the cost of another person. That's not why Christ paid the price for our forgiveness and freedom.