<<The assembly of Christians was always referred to as the Church of God.>>
The term "church of God" found in the NT has absolutely nothing to do with the modern, western, aberration of Christianity called the "Church of God."
<< We observe God's Holy Day festivals as prescribed in the Bible >>
Do you put the blood of a lamb on the doorposts of your house every Passover?
No you don't.
Do all the male members of the "Church of God" go to Jerusalem three times a year to present themselves before the Lord?
No they don't.
On the tenth day of the seventh month, the day of atonement, do you incinerate an animal on an altar?
No you don't.
And do you offer a sacrifice by fire (incinerate an animal on an altar) every day for eight days to celebrate the feast of tabernacles?
No you don't.
So, please. Don't delude yourself into thinking that you "keep the feasts." That's utter nonsense. If you bothered to read the scriptures that say EXACTLY HOW to keep those feasts, you would realize that you do NOT keep them according to God's commandments.
<<Keeping the Sabbath on a Sunday the first day of the week is a violation of the fourth commandment. Sunday keeping is a man-made tradition, not sanctioned by God.>>
No one "keeps the Sabbath" on Sunday. If they did, they wouldn't get into their cars and drive for miles to get to Church because God told the Jews to stay where they are on the Sabbath. ( EX 16:29 )
Sunday is the day on which the Lord rose from the grave. The real Church has celebrated His resurrection on the first day of the week since the beginning. They did so by assembling together for the reading of scripture and the Eucharist.
The Teaching of the Apostles. (1st Century)
The apostles further appointed: On the first day of the week let there be service, and the reading of the Holy Scriptures, and the oblation: because on the first day of the week our Lord rose from the place of the dead and on the first day of the week He arose upon the world, and on the first day of the week He ascended up to heaven, and on the first day of the week He will appear at last with the angels of heaven.
The Epistle of Ignatius to the Magnesians
C. 50-117 AD, Bishop of Antioch
Chapter IX.—Let Us Live with Christ.
If, therefore, those who were brought up in the ancient order of things have come to the possession of a new hope, no longer observing the Sabbath, but living in the observance of the Lord’s Day …
…And after the observance of the Sabbath, let every friend of Christ keep the Lord’s Day as a festival, the resurrection-day, the queen and chief of all the days [of the week]. Looking forward to this, the prophet declared, “To the end, for the eighth day,” on which our life both sprang up again, and the victory over death was obtained in Christ, …
…At the dawning of the Lord’s day He arose from the dead, according to what was spoken by Himself, “As Jonah was three days and three nights in the whale’s belly, so shall the Son of man also be three days and three nights in the heart of the earth.” The day of the preparation, then, comprises the passion; the Sabbath embraces the burial; the Lord’s Day contains the resurrection.
The Epistle of Barnabas C. 70-131AD
Chapter XV. The False and the True Sabbath.
…. Further, He says to them, “Your new moons and your Sabbath I cannot endure.” Ye perceive how He speaks: Your present Sabbaths are not acceptable to Me, but that is which I have made, [namely this, ] when, giving rest to all things, I shall make a beginning of the eighth day, that is, a beginning of another world. Wherefore, also, we keep the eighth day with joyfulness, the day also on which Jesus rose again from the dead. And when He had manifested Himself, He ascended into the heavens.
And the Sabbath is a sign between Israel and the Lord, ( EX 31:17) not between Gentiles and the Lord. Are you Jewish? If so, keep the Sabbath. If not, then don't worry about it.
If you think you keep the Sabbath then you have to do all of the following:
EX 16:29-30 Bear in mind that the LORD has given you the Sabbath; that is why on the sixth day he gives you bread for two days. Everyone is to stay where he is on the seventh day; no one is to go out." So the people rested on the seventh day.
Don’t travel on the Sabbath. (Keep any walking under 1 mile each way)
EX 20:8-10 Remember the Sabbath day by keeping it holy. Six days you shall labor and do all your work, but the seventh day is a Sabbath to the LORD your God. On it you shall not do any work, neither you, nor your son or daughter, nor your manservant or maidservant, nor your animals, nor the alien within your gates.
1. Don’t you or anyone in your household do any work on the Sabbath.
2. It also includes animals which have been replaced by cars, trucks, tractors, buses, airplanes, trains, etc., So don’t work and don’t use a motor vehicle on the Sabbath.
EX 31:14-17 Observe the Sabbath, because it is holy to you. Anyone who desecrates it must be put to death; whoever does any work on that day must be cut off from his people. For six days, work is to be done, but the seventh day is a Sabbath of rest, holy to the LORD. Whoever does any work on the Sabbath day must be put to death. The Israelites are to observe the Sabbath, celebrating it for the generations to come as a lasting covenant. It will be a sign between me and the Israelites forever, for in six days the LORD made the heavens and the earth, and on the seventh day he abstained from work and rested.
1. The seventh day is for rest; do not work on the Sabbath.
2. Israelites are to observe the Sabbath. (not gentiles, Israelites)
3. The Sabbath is a sign between God and Israel. (Again: Israel; not gentiles)
4. God abstained from work and rested on the 7th day and Israel (not Gentiles) is to do the same.
EX 35:1-3 Moses assembled the whole Israelite community and said to them, "These are the things the LORD has commanded you to do: For six days, work is to be done, but the seventh day shall be your holy day, a Sabbath of rest to the LORD. Whoever does any work on it must be put to death. Do not light a fire in any of your dwellings on the Sabbath day."
1. The command concerning keeping the Sabbath Holy came from the LORD not from Moses.
2. Rest on the Sabbath and do no work.
3. Do not light a fire in your dwelling on the Sabbath. (Furnace, oven, light bulb)
LEV 23:3 There are six days when you may work, but the seventh day is a Sabbath of rest, a day of sacred assembly. You are not to do any work; wherever you live, it is a Sabbath to the LORD.
DT 5:12-14 Observe the Sabbath day by keeping it holy, as the LORD your God has commanded you. Six days you shall labor and do all your work, but the seventh day is a Sabbath to the LORD your God. On it you shall not do any work, neither you, nor your son or daughter, nor your manservant or maidservant, nor your ox, your donkey or any of your animals, nor the alien within your gates, so that your manservant and maidservant may rest, as you do.
Don’t use any utility (electricity, gas, internet, telephone, etc.) or public service (roads, police, radio, TV, bus, etc.) that requires anyone to work on the Sabbath in order to provide the service.
<< We maintain tithing in accordance with our responsibility to honor the Lord as an act of worship and a means to which the gospel is proclaimed to the world. >>
There is no New Testament instruction for Christians to tithe.
So, when you tithe, do you take your tithe to Jerusalem and have a party to celebrate all that the Lord has done for you? No? That's that the scripture specifically tells you to do.
Deu 14:22-25
You shall truly tithe all the increase of your grain that the field produces year by year. And you shall eat before the LORD your God, in the place where He chooses to make His name abide, the tithe of your grain and your new wine and your oil, of the firstborn of your herds and your flocks, that you may learn to fear the LORD your God always.
But if the journey is too long for you, so that you are not able to carry the tithe, or if the place where the LORD your God chooses to put His name is too far from you, when the LORD your God has blessed you, then you shall exchange it for money, take the money in your hand, and go to the place which the LORD your God chooses. And you shall spend that money for whatever your heart desires: for oxen or sheep, for wine or similar drink, for whatever your heart desires; you shall eat there before the LORD your God, and you shall rejoice, you and your household.
And every third year do you take your tithe to the storehouse where it can be distributed to the widow, the orphan, the alien, and the Levite as you are commanded to do at Deuteronomy 14:28-29?
Is that what you do?
No, of course not. You're just pretending to tithe.
<<... they have laid aside God's days and honor their own traditions like Christmas and Easter.>>
Christmas is the celebration of the birth of Jesus, His first advent. Why would you have a problem with that?
Easter, which is called "Pascha" (Passover) in non-English speaking countries, is the celebration of Christ's resurrection from death. The resurrection is the most important event in the Christian faith. And you foolishly call it "paganism" rather than to celebrate what God has done for you.
Paul said that Christ's resurrection was essential to your faith.
1Co 15:14-17 And if Christ is not risen, then our preaching is empty and your faith is also empty. Yes, and we are found false witnesses of God, because we have testified of God that He raised up Christ, whom He did not raise up—if in fact the dead do not rise. For if the dead do not rise, then Christ is not risen. And if Christ is not risen, your faith is futile; you are still in your sins!
<<Do you think it matters to God whether we keep the Holy days He instituted?>>
Only if you are a Jew. (A real Jew, not a pretend Jew who makes up his own junk about what to do on the feasts and about tithing instead of doing exactly what God said to do)
Those festivals and the tithe are part of the Law. If you think you must keep them in order to be saved then you are under a curse.
Gal 3:10 For all who rely on works of the law are under a curse; for it is written, "Cursed be every one who does not abide by all things written in the book of the law, and do them."
Paul is talking to YOU.
Since you believe you must keep part of the Law in order to be saved, it is necessary for you to keep ALL of the Law. And since you are 100% unable to do that, you are condemned and so is your entire pretend-Jew denomination led by false teachers who are teaching you "another gospel". (Gal 1:6-7)
Those teachers are accursed. (Gal 1:8-9)
And when you spread that "other" gospel of keeping the Law, you are also accursed.
Rom 3:20 For no human being will be justified in his sight by works of the law, since through the law comes knowledge of sin.
Rom 3:28 For we hold that a man is justified by faith apart from works of law.
Gal 2:16 yet who know that a man is not justified by works of the law but through faith in Jesus Christ, even we have believed in Christ Jesus, in order to be justified by faith in Christ, and not by works of the law, because by works of the law shall no one be justified.