It's Just a Day
When talking about the Sabbath/Sunday issue, so many people say: It's just a day!.
But it's not like that at all. Keeping the Sabbath is a commandment.
For example, what if I say to you: From now on I will celebrate your birthday on the 31st of September, because it suits me better.
Do you see how crazy that is?
God wants to celebrate the Sabbath with you, but it's on the seventh day, and it will never change.
Do you love God enough to keep this commandment?
If ye love me, keep my commandments.
- John 14:15 (KJV)