Rom. 14:1 Accept Christians who are weak in faith, and don't argue with them about what they think is right or wrong.
Some Christians are stronger in faith than others. There are many reasons why it is so. New believers tend to live on emotions more than Biblical understanding. Most of them are not grounded in truth and have not had time to develop an understanding of it. Many are in the process of developing disciplines that will help them to grow, but they are not firmly established yet and so their growth is sporadic.
There are also many of us who simply never grow up; they remain weak in faith. They lack commitment to the disciplines of faith and so they just sort of wander through life knowing Christ on a very weak foundation. They struggle greatly in their ability to resist temptations. They are sporadic in their commitment to church life. They believe, but have a difficult time with applying what they believe to their living.
Weak Christians tend to be more reactive than more established believers. They are quicker to argue over things because they are more defensive. They have little understanding of how some things can be understood by others in different ways and lived out differently. They are not prone to be gracious with those who they don't agree with.
We accomplish nothing by being argumentative. We aren't always going to agree with one another on everything we know to be true. We aren't going to persuade very many people by arguing with them over details. Instead, we should be gracious towards one another and agree to disagree agreeably and serve the Lord together in peace. We are to love one another and not be at odds with one another over things we don't agree on. Let the Spirit of Christ guide into all truth and do your best to serve the Lord with your best for His honor and glory.