Remember the Sabbath day, to keep it holy
Today Sunday is just like any other day of the week. It isn't special anymore. People still work, and do anything that they would do on a normal weekend. Now I am not saying that you shouldn't work on Sunday. I work practically every single Sunday after church, but we need to set a time on our Sundays to spend with God. We still need to keep his day holy and sacred. The Bible does say that we need to give God the first of everything. Sundays are the first day of the week, so we need to set aside that day for Him.