Okay, we need to turn to our bibles.
In Exodus 20:8-11 it says
8 "Remember the Sabbath day by keeping it holy. 9 Six days you shall labor and do all your work, 10 but the seventh day is a Sabbath to the LORD your God. On it you shall not do any work, neither you, nor your son or daughter, nor your manservant or maidservant, nor your animals, nor the alien within your gates. 11 For in six days the LORD made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy.
God NEVER changed the Saturday Sabbath to Sunday. That is why Seventh-Day Adventist go to church on Saturday as there Sabbath.
Also, Mark 16:1-3
1When the Sabbath was over, Mary Magdalene, Mary the mother of James, and Salome bought spices so that they might go to anoint Jesus’ body.
2Very early on the first day of the week, just after sunrise, they were on their way to the tomb 3and they asked each other, “Who will roll the stone away from the entrance of the tomb?”
Jesus rose on the day which is known today as Sunday.Mary Magdalene went down to the tomb on Sunday morning which is the day Jesus rose. This text shows Sunday is the first day of the week.
Also, In some languages such as spanish, the same word used as Sabbath means the same as Saturday.Example: sábado means Sabbath and Saturday in spanish.
The Catholic church started during the dark age when all the bibles where locked away. The catholics started to tell the people what was right from what was wrong the the people couldn’t challenge the church on their beliefs because they never had any bibles.
If you have any questions, feel free to PM me or post on this forums.