Different denominations do that? I didn't know that. You mean they rearrange the order? Isn't the order in the Bible?
Q:Why are the Ten Commandments not written in the same order anymore? The fourth is now the fifth. Why? I'm a Roman Catholic and can't find the commandments written the way I learned them.
A: Your confusion has a 2,000-year history. Since Judaism and Christianity split, there's been no disagreement that there are 10 commandments listed in Exodus and (in a very similar version) in Deuteronomy; there's just no agreement on which commandment should bear which number.
Starting with Augustine, Catholics, and then later, Lutherans, combined commandments 1 and 2 and then, so that they could still get to 10, they separated the commandment about coveting into two separate commandments -- one prohibiting the coveting of your neighbor's possessions and one prohibiting coveting your neighbor's wife. What this has meant is that commandments 2-10 are numbered differently in each list.