"God is Spirit, and those who worship Him must worship in spirit and truth" - John 4:24
"On the first day of the week... to break bread" (Acts 20:7)
"Speaking to one another in psalms and hymns and spiritual songs" (Ephesians 5:19)
"Pray without ceasing" (1 Thessalonians 5:17)
"Preach the word" (2 Timothy 4:2)
"On the first day of the week let each one of you lay something aside" (1 Corinthians 16:2)