“It means that when all the bishops come together in council, and prayerfully address a controversy, they can count on the Holy Spirit to lead them to agreement. Christ had said to expect that guidance, for the Holy Spirit would ‘guide you into all the truth’ (John 16:13)”.
“When the gathered bishops find consensus, they give thanks for the Holy Spirit’s guidance, but there’s one more step to go, for the rest of the Church, back home, must confirm their decision. The bishops return home, their decision is released, and the clergy, laypeople, and monastics hear it and weigh it. If they accept it (or as it’s said ‘receive’ it), that seals the truth of the bishops decision”.
“So in the East, theology is not defined by a powerful leader or a panel of experts. The guarding of the Christian faith is the responsibility of every member of the body of Christ, right down to a circle of grannies in a remote rural parish.”
[in case you’re wondering]
“… It’s possible for the laity to reject and thereby void a a council’s decision. In the fifteenth century at a council in Florence, all but one of the Eastern delegates agreed to sign a document placing the Orthodox Church under the authority of Rome. The delegates’ hope was that, in return, Rome would supply military aid against the Ottoman Empire, which was at Constantinople’s gates.”
“But when this agreement was carried back to the Orthodox faithful, it was emphatically rejected. The agreement was made void, the West did not send help, and the East was overrun by Muslim conquerors, who still control much of the land to this day. The Orthodox Church recognizes as a saint the single delegate who refused to sign: St. Mark of Ephesus.”
—— Frederica Mathewes-Green, Welcome To The Orthodox Church, An Introduction To Eastern Christianity