Do you participate in communion service? If so, why?
Is it to remember what Jesus did for us or do you worship the bread and wine?
Keeping the Sabbath holy, as God commands, is not worhiping the day, but rather, worshiping the one who commands us to keep the Sabbath holy.
You can gather in fellowship seven days a week and praise God if you do but you can't keep the seventh day holy seven days a week.
Obeying God over man is foundational for true worship.
Matthew 15:9 Their worship is worthless, for they teach their man-made laws instead of those from God.''
You can't say the Sabbath is seven days a week because the seventh day Sabbath is a literal day in which our sons, daughters, male and female servants, our working animals and even the stanger must cease secular labor as a means to acknowledge the holiness of the seventh day.
Now as far as Sunday worship goes, you ask the question of what is Sunday worship as though you don't know. I have to refer you to my website exposingantichrist.com because it is there that you will see the big picture and the spiritual battle over worship.
Revelation 14:6-10 Then I saw another angel flying in the midst of heaven, having the everlasting gospel to preach to those who dwell on the earth to every nation, tribe, tongue, and people saying with a loud voice, "Fear God and give glory to Him, for the hour of His judgment has come; and worship Him who made heaven and earth, the sea and springs of water.'' And another angel followed, saying, "Babylon is fallen, is fallen, that great city, because she has made all nations drink of the wine of the wrath of her fornication.'' Then a third angel followed them, saying with a loud voice, "If anyone worships the beast and his image, and receives his mark on his forehead or on his hand, "he himself shall also drink of the wine of the wrath of God, which is poured out full strength into the cup of His indignation. And he shall be tormented with fire and brimstone in the presence of the holy angels and in the presence of the Lamb.