As has been discussed, humans are naturally creatures of habit. This is problematic, for if you do something one way long enough, you begin to think it is the only way. Couple this mentality with religion and you have a perfect storm for dogmatism.
If a routine is tied to religious practice you begin to believe that not only is it the only way, and the best way, but it must also be the Godly way. When you observe a religious practice that differs from your own, your engrained response (articulated or not) is “that must be condemned in the Bible somewhere!”.
The solution to this type of mentality is honest Bible study, but the problem is all of us bring baggage to the Bible when we study it. It is natural to read your current situation into the text instead of reading it through the lens of the original reader.
Consider the example of communion on the first day of the week. Our church takes the Lord’s Supper on Sundays. Often the one presiding over the service will read Acts 20:7 which states:
“On the first day of the week, when we were gathered together to break bread, Paul talked with them, intending to depart on the next day, and he prolonged his speech until midnight”
It is natural to assume that “the first day of the week” is the day we call “Sunday”. We probably picture these early Christians gathering together in what we would consider a Sunday evening assembly. Were you aware that the Jewish way of determining a day was sunset to sunset? This means that the “first day of the week” being mentioned in this passage is most likely what we would call Saturday night. This is not a big deal, but it serves to illustrate a point. How many times have we read that passage and saw it through our midnight to midnight way of viewing a day vs. sunset to sunset.
We must be careful to not bring baggage to the text, and when we do, at least be open enough to acknowledge it. An ancient writer is quoted as saying, “It is impossible to teach someone something he thinks he already knows.” If we are convinced that we already know what the correct teachings of Scripture are, then we can read Scripture over and over and yet never see anything different from what we already believe. To be open to receive truth, we must start with a blank slate (Bercot).