Is Sunday taught in the Bible?
No, Sunday is not taught in Scripture as a special holy day. Paul says to regard every day alike, and the book does not set Sunday above the other six days. Every day is alike for the believer, who serves God just as much Monday through Friday as Saturday and Sunday.
Les explains that in this age of grace, Christ nailed the system of worship to His cross, and believers are free. Paul says not to regard one day higher than another, but to regard every day alike. Les notes that even Sunday is not taught in the Scriptures as we understand Sunday. Paul merely said that as believers come together and bring their offerings, it can be on the first day of the week, resurrection day. But setting Sunday up as a special holy day above the other six days is not taught in the book. Every day is alike for the believer, who is to serve God just as much Monday through Friday as Saturday and Sunday. Les also connects this to Galatians 4, warning against legalism that tries to satisfy the ego.