They argue that the custom of meeting for worship on Sunday originated in paganism , specifically Sol Invictus and Mithraism -LRB- in which sun-god worship took place on Sunday -RRB- and constitutes an explicit rejection of the commandment to keep the seventh day holy .

They argue that the custom of meeting for worship on Sunday originated in paganism , specifically Sol Invictus and Mithraism -LRB- in which sun-god worship took place on Sunday -RRB- .
