Complex sentence: Since Puritan times, most English-speaking Protestants equate "Lord's Day" (viz., Sunday) with "Sabbath", as do Roman Catholics; kept in commemoration of the resurrection of Christ, it is often celebrated with the Eucharist.
Split into simpler sentences: Since Puritan times, most English-speaking Protestants equate the "Lord's Day" (viz., Sunday) with "Sabbath", as do Roman Catholics. Kept in commemoration of the resurrection of Christ, it is often celebrated with the Eucharist.