Sunday is a day of sabbath for christians
The Resurrection, which took place on Sunday. Christians honour that as their sabbath.
Yes and no. The Jewish word for Sabbath is "Shabbat." Christians just say Sabbath.
No, the Christians did.
Yes. The Christian Sabbath is celebrated by Christians on Sunday. Jews celebrate the Sabbath from Friday sunset until Saturday after twilight.
Jews worship the sabbath from Friday eve to Saturday eve. Christians worship the Sabbath on Sunday. I am not sure about non-Christians, or non-Jews.
Christians have always worshiped on the Sabbath
The question makes invalid assumptions. That the Pope represents all Christians. That the Pope believes the Sabbath presently worshipped is incorrect. That the Pope has the ability to change that Sabbath
Sunday
To obey God.
Yes, for Christians.
Good strong Christians. It is hard. But it is possible.