Common faith makes a common church, no matter who and where the believers are.—1 Cor. 1:10, 13.
... 19. In which respect was the early Christian church something never seen before?
19 Indeed the church was a wonder and an outstanding exception in the history of mankind; an international organization, yet characterized by “one heart and soul,” “same mind,” and “same line of thought,” ‘one body, one spirit, one hope, one Lord, one faith, one baptism, one God and Father.’ (Acts 4:32; 1 Cor. 1:10; Eph. 4:4-6)