Part of the reason we question others is because they might do things differently than us. This was also one reason these men questioned Jesus that day in Mark 2:18-22 (with Matt 9:14-17 and Luke 5:33-39 in parenthesis):
Once when John’s disciples and the Pharisees were fasting, some people (the disciples of John the Baptist) came to Jesus and asked, “Why don’t your disciples fast like John’s disciples and the Pharisees do?” (Why are your disciples always eating and drinking?)
When we see someone else doing something different than us we naturally ask that first question, "Are we doing the right thing?". Differences can scare us especially when we think our way is the right way.
They have a legitimate question for Jesus. "Why are you different than us?" they ask.
Different doesn't always equate to right/wrong. Certainly, there are times where differences can be life or death and in those times we must deal with them. There are certain things we must agree on (Jesus, Salvation, Grace, etc.). There are other times where differences just hang us up and stall us out.
John The Baptist's disciples were waiting for The Messiah and they fasted and prepared for His Coming. This was a good thing. They had not yet met Jesus and now that they had they did not need to fast...they needed to believe and celebrate. Jesus disciples were hanging out with God so they celebrated. This was a good thing. Rather than the two groups being polarized in their differences they needed to unite in their similarities. For both, God was at the center. For both, they wanted to walk in a manner that pleased God.
There will be differences in this life that do need to be settled but many differences are ok. Different colors, languages, cultures...all One Race...the Human Race. Different preferences, styles of church...all One Body. Different traditions, denominations, gifts...all One Faith. How much energy does the Devil help us waste when we argue over differences rather than work within our commonalities?
It can often be your differences that cause others to look at you and see God at work in your life. Why is he/she so happy? How can he/she forgive that person? Where does his/her strength come from? Our differences can point to the power of Christ at work in us! Let it be so today!