I wasn't sure if it was okay to reply here, but you did say that non Adventists are free to reply. So here goes. This is the main reason why I don't believe in keeping of a Sabbath:
Romans 14:5: "One man esteems one day above another: another esteems every day alike. Let every man be fully persuaded in his own mind."
Paul clearly and irrefutably says that it does not matter which day a person chooses to gather in fellowship to worship. That to honor one day is okay for sure, but to honor every day equally is also okay.
When you consider the context in which Paul was speaking it is clear that Paul wasn't referring to a sabbath day.
Rom 14:1¶Him that is weak in the faith receive ye, [but] not to doubtful disputations.
Should we consider that Paul thought the Ten Commandments were "doubtful disputations"?
The following is from:
http://www.sabbath-truth.org/sabbath-truth.html
"To begin with, it must be admitted that the word Sabbath is not found in the entire chapter. People assume Paul is talking about the Sabbath. But is he really? The chapter begins, Him that is weak in the faith receive ye, but not to
doubtful disputations. Romans 14:1. The NKJV reads, disputes over doubtful things. This chapter concerns doubtful things and is not a discussion of the Ten Commandments. The Big Ten are not doubtful, but exceedingly dear, written with the finger of God on two tables of stone. The weak brother eats some things and esteems one day above another while the strong brother believes that he may eat all things and esteems every day alike. Romans 14:2, 5. The early Church was made up of Jewish believers and Gentile converts. Although Paul did not specify what days he was referring to, he was probably talking about the esteemting or not esteeming of certain Jewish fast or feast days (Luke 18:12), and certain pagan feast days when people were especially eating of those things that are offered in sacrifice unto idols. 1 Corinthians 8:4.
A strong Jew who knew that an idol is nothing would have no scruples about eating meat in an idols temple on a pagan feast day. 1 Corinthians 8-4, 10. Paul warned these strong Jewish believers, But take heed lest by any means this liberty of yours become a stumbling block to them that are weak [the Gentile convert from idolatry]. For if any man see thee which hast knowledge sit at meat in the idol's temple [on a pagan feast day], shall not the conscience of him that is weak be emboldened to eat those things which are offered to idols; and through thy knowledge shall the weak brother perish [if he is drawn back to idolatry], for whom Christ died. But when ye sin against the brethren, and wound their weak conscience, ye sin against Christ. Wherefore, if meat make my brother to offend, I will eat no flesh while the world standeth. 1 Corinthians 8:9-13.
THERE IS NO EVIDENCE that the discussion about the weak and the strong in Romans 14 and 1 Corinthians 8 has ANYTHING TO DO WITH THE SABBATH. God has never said one man may choose to esteem MY Sabbath, while another man may choose to esteem Sunday, or every day alike. He has not left it up to us to pick a day, any day. Rather, God has commanded,
Remember the sabbath day to keep it holy ... the seventh day is the sabbath of the Lord thy God. Exodus 20:8, 10. The book of Romans is very clear, by the law is the knowledge of sin. Romans 3:20; 7:7, 12."
Also, Jesus says clearly that the greatest commandments are to love God with all your heart, soul and mind and to love your neighbour as yourself.
Does that seem reasonable?
BS, are you aware that commandment which Jesus mentioned is an "old covenant" teaching?
Lev 19:18 Thou shalt not avenge, nor bear any grudge against the children of thy people, but
thou shalt love thy neighbour as thyself: I [am] the LORD.