Rev 1, 20b Seven lampstands are the seven churches

(Rev 1, 20b) Seven lampstands are the seven churches
[20b] and the seven lampstands are the seven churches.

(CCC 833) The phrase "particular church," which is the diocese (or eparchy), refers to a community of the Christian faithful in communion of faith and sacraments with their bishop ordained in apostolic succession (Cf. CD 11; CIC, cann. 368-369; CCEO, cann. 177,1; 178; 311, 1; 312). These particular Churches "are constituted after the model of the universal Church; it is in these and formed out of them that the one and unique Catholic Church exists" (LG 23). (CCC 834) Particular Churches are fully catholic through their communion with one of them, the Church of Rome "which presides in charity" (St. Ignatius of Antioch, Ad Rom. 1, 1: Apostolic Fathers, II/2, 192; cf. LG 13). "For with this church, by reason of its pre-eminence, the whole Church, that is the faithful everywhere, must necessarily be in accord" (St. Irenaeus, Adv. haeres. 3, 3, 2: PG 7/1, 849; Cf. Vatican Council I: DS 3057). Indeed, "from the incarnate Word's descent to us, all Christian churches everywhere have held and hold the great Church that is here [at Rome] to be their only basis and foundation since, according to the Savior's promise, the gates of hell have never prevailed against her" (St. Maximus the Confessor, Opuscula theo.: PG 91, 137-140). (CCC 835) "Let us be very careful not to conceive of the universal Church as the simple sum, or… the more or less anomalous federation of essentially different particular churches. In the mind of the Lord the Church is universal by vocation and mission, but when she puts down her roots in a variety of cultural, social, and human terrains, she takes on different external expressions and appearances in each part of the world" (Paul VI, EN 62). The rich variety of ecclesiastical disciplines, liturgical rites, and theological and spiritual heritages proper to the local churches "unified in a common effort, shows all the more resplendently the catholicity of the undivided Church" (LG 23).