It is frequently asserted, without authority from Scripture, that God accepts our worship on any day, thus any day of the week is suitable for worship services. Some use Romans 14:5-6, Galatians 2:10, and/or Colossians 2:16 to make their point in this regard. However, their reasoning on these verses is fallacious.
It is true that God desires us to worship Him every day. We should constantly be in an attitude of worship (Psalm 16:8; John 8:29), doing everything at all times to His glory (I Corinthians 10:31). However, as to a holy day of worship, God has commanded only one, the seventh day (Leviticus 23:3), and since the time He gave this commandment, He has set apart no other day.
By His example at Creation, God showed mankind which day He sanctifies (Genesis 2:3). By the time He freed the Israelites from slavery in Egypt, they had evidently forgotten which day to keep. By giving them twice the amount of manna on the sixth day and none on the seventh, God reestablished which day was to be the day of worship (Exodus 16:22-30). This sign of the Sabbath day continued for almost forty years, so that Israel would never forget which day God had chosen. Incidentally, this occurred a month before God gave the law from Sinai.
God has never made a change in His command. In the New Testament, Jesus and His disciples kept the Sabbath, and after the resurrection, the early church continued to hold its worship services on the seventh-day Sabbath. God has made a perpetual weekly appointment on the Sabbath day for us to meet with Him (see Exodus 31:13-17). He is present for that purpose on no other day.