The truth is, if Sunday or first day observance was taught in scripture, revealed a doctrine by either Jesus our the apostles, practiced by the first century church, then those who oppose Sabbath keeping would cite the very verses that reveal such, and their case would be settled. But they don't, and they can't. So they resort to philosophy, a expressed above by the concept of"Jesus being our Sabbath test", a concept nowhere to be found in scripture.
This is the reason the CC should have included the Epistle of Barnabas in the canon. It was fought for and on six different lists of candidates. It was read in all the early churches and believed by them to have been written by the apostle Barnabas.
Is this clear enough for you? It is for me:
Barnabas 15:8
Finally He saith to them;
Your new moons and your Sabbaths I cannot
away with. Ye see what is His meaning ; it is not your present
Sabbaths that are acceptable [unto Me], but the Sabbath which I have
made, in the which, when I have set all things at rest, I will make
the beginning of the eighth day which is the beginning of another
world.
Barnabas 15:9
Wherefore also we
keep the eighth day for rejoicing, in the which
also Jesus rose from the dead, and having been manifested ascended
into the heavens.
Don't you agree that if we had this book many errors could have been prevented? A law specifically about abortion is no where in our 66 books. But it is in the Epistle of Barnabas.
Barnabas 19:5
Thou shalt not doubt whether a thing shall be or not be.
Thou shalt
not take the name of the Lord in vain. Thou shalt love thy
neighbor more than thine own soul.
Thou shalt not murder a child by
abortion, nor again shalt thou kill it when it is born. Thou shalt
not withhold thy hand from thy son or daughter, but from their youth
thou shalt teach them the fear of God.