All Christians observe the Passover, not just Jewish believers. It's called the Lord's Supper now, but both ordinances celebrate the same thing - the sacrifice of the Lamb of God.

All believers observe the Sabbath, but we call it "the Lord's day" now.

All Christians (including Gentile believers) are to observe covenantal "circumcision" (of the heart) through baptism. The two New Testament sacraments and the Lord's Day are the "forever" applications of the Old Testament ordinances.