How do I explain and defend Sunday worship?

A non-Catholic Christian(?) asked me where in the Bible does it say the day of worship is now Sunday instead of the Sabbath (Saturday). Some dates and writings of early Church Fathers may be helpful, but I’m not sure. Most people know Jesus rose on Sunday, but that in itself does not help him accept the day change.
Thanks and God Bless

The following link should help you better understand the Church’s teaching on keeping the Sabbath day holy. If you have any further questions, please contact Catholic Answers directly.

Recommended Reading:

*] Where is the Sunday Mass obligation in the Bible?
*] Do Catholics observe the Sabbath?
*]Why do Catholics worship on Sunday?
*]Seventh-Day Adventism
*]Sabbath or Sunday?
*]From Sabbath to Sunday by James P. Guzek

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