Romans 14:1 "Receive one who is weak in the faith,but not to disputes over doubtful things. 2 For one believes he may eat all things, but he who is weak eats only vegetables. 3 Let not him who eats despise him who does not eat, and let not him who does not eat judge him who eats; for God has received him. 4 Who are you to judge another’s servant? To his own master he stands or falls. Indeed, he will be made to stand, for God is able to make him stand."
Remember as we go that the main theme of Romans is the Good News that in Jesus there are no borders, colours, or races. He has no favourites. We are all His and all equal. This was a radical concept in 1st century Palestine and remains just as radical today but no less true.
The specific issue in these verses is dealing with differences of opinion and understanding in the body of Christ. One point of contention back then was over food. Piecing clues together from other letters in the New Testament we discover that it was common practice for food, especially meat, to be offered to pagan gods as an act of thanks/worship and then sold to the public in the market.
Christians were of two minds on this. Some felt the fact that the meat was associated with idol worship made it "tainted" and they would not eat it. Others believed that since idols were only wood, stone, or metal that it was pure foolishness and had no problem eating it. Rather than choose a side Paul takes a radical third position. He essentially says "Do what you believe is right and respect each other without judgment even if you disagree."
Paul are you saying??? Doesn't the Bible say "How can two walk together unless they be agreed?"
Yes the Bible says that.
So then is Paul contradicting the Word of God? Hardly. It is essential we agree on the important things but Paul says this is a "doubtful matter". Both sides make a valid point. Both show reverence for God and a disdain for idols. They just express it differently.
Not all roses are red yet they are all roses.
If we insist that others must see things our way on every issue to be a "true Christian" then we are going to be a cause of misery to others and ourselves plus we are ignoring the direct counsel of God. Some say live and let live. Some say in essentials unity, in non essentials liberty, and in all things charity (love).
I say follow Jesus.