Why the Sunday-keeping Church thinks of Sunday as the Sabbath

We, NOT ONCE in the NT, 'see' the disciples of Christ, 'worship', on the First Day of the week ('Sunday') - and not at all, in Acts 20:7. In this text we 'SEE' by way of the Perfect Participle "Paul, AFTER the disciples HAD HAD ASSEMBLED TOGETHER FOR TO HAVE THE LORD'S SUPPER they STILL BEING TOGETHER on the evening of the First Day, dealt with them ..." on matters other, than they originally HAD HAD ASSEMBLED TOGETHER, for.

 

'there is no "sabbath" under the NT'
A VERY wrong, statement, in view of the FACT, we SEE the NT Church as a whole and undivided, observing and keeping holy BY FAITH IN JESUS CHRIST, the 'Sabbath Day' (Seventh Day of the week) for years AFTER the other documents of the NT Church were written, IN, the GOSPELS, written, decades later.

 

We indeed see this NT Church from its inception, "Feast(ing) Sabbaths'-Feast" (Colossians 2:16-19) in the face of the persecutor, the world, ON THE GROUNDS OF JESUS' TRIUMPH THROUGH RESURRECTION FROM THE DEAD, Colossians 2:12-15!

 

We indeed see this very Church of Christ's Own, doing its money-dealings - even for charity - on the First Day of the week -- so 'strictly' as to avoid doing it on the Sabbath Day. (1Cor16:1f)

 

We indeed behold the first believers in and followers of Christ Jesus keeping Sabbath TOGETHER WITH this One their Lord, God and Saviour, as His custom was, during whole His ministry of Salvation, and following through to ultimate consequence their faith in Him Lord of the Sabbath Day IN SCRIPTURE, on the very event of His obtaining LORDSHIP of the Sabbath Day, on the very event of His rising from the dead "In the fulfilment of the Sabbath", Mt28:1.

 

We SEE - as Israel of old never could - "the Month of Abib observed" BY, "CHRIST OUR PASSOVER LAMB", DAY FOR DAY, HOUR FOR HOUR, TO THE LETTER ... "the eighth day"; "the tenth day"; "the fourteenth day"; "the fifteenth day"; "the sixteenth day" --- "Six days before the Passover Feast", "the next day" .... "the day before the the Feast Day", "a high day-sabbath", "the Fore-Sabbath" : "In the Sabbath Day's fulness".
If ever the Scriptures confirm a day in the dispensation of God Almighty Faithful, it is "the Seventh Day Sabbath of the LORD your God" "For thus God concerning the Seventh Day spake".

 

This is the day the LORD has MADE, let us rejoice in it, says the Psalmist. This is Abib 16 announced : With the Song of Moses and of the Lamb; the ONLY day in The Promise announced by the 'last trump', the trumpet of resurrection-day --- the Sabbath Day. (2Chron29)

 

TC Greek
Today, this side of the cross, we don't have the same injunction to keep the Jewish Sabbath.

GE
Think of it this way, Today, this side of the cross, we don't have the same injunction to keep the Sabbath Jewish, but Christian, which is, to keep it, not for the reasons the first humans might have - creation; or, not for the reasons the Jews might have - their exodus from Egypt, but, for the sole reason of Jesus Christ having brought us - believers - in into the Rest of God through Him, on the Day He Rested and finishe all the works of God on, the Sabbath Day - Seventh Day of the week. Christian faith that isn't Resurrection-Faith is neither Christian, nor Faith!