<Li> Seventh - day Adventist scholar Samuele Bacchiocchi has argued that Sunday worship unconnected to Sabbath was introduced in Rome in the 3rd century, and was later enforced throughout the Christian church as a substitution for Sabbath worship . There is evidence of early Christians simultaneously observing both seventh - day Sabbath rest and Sunday worship, and Socrates Scholasticus states that 4th - century Rome had ceased to worship on Sabbath, while Alexandria held its love feasts or Eucharists on the first day, substituting it for Sabbath as kept in other churches . </Li> <P> On 3 March 321, Constantine I decreed that Sunday (dies Solis) will be observed as the Roman day of rest (CJ3. 12.2): </P> <P> On the venerable day of the Sun let the magistrates and people residing in cities rest, and let all workshops be closed . In the country however persons engaged in agriculture may freely and lawfully continue their pursuits because it often happens that another day is not suitable for grain - sowing or vine planting; lest by neglecting the proper moment for such operations the bounty of heaven should be lost . </P> <P> Constantine's decree was most likely modeled on pagan sun worship, though it is probable that he also intended to benefit the church, which already met for worship on Sunday . </P>

When did christian start to worship on sunday