3 From the consideration of this event and its attendant circumstances, two points arise and stand out, and these we wish, as far as possible, to make yet more clear. They are: the primacy of the Roman pontiff which shone forth clearly in this very grave christological controversy and, secondly, the great importance and weight of the dogmatic definition of Chalcedon. Let those who, through the evils of the time, are separated from the bosom and unity of the Church, especially those who dwell in Eastern lands, not delay to follow the example and the customs of their ancestors in paying due respect to the Roman primacy. And let those who are involved in the errors of Nestorius or Eutyches penetrate with clearer insight into the mystery of Christ and at last accept this definition in its completeness. Those, also, who are led by an excessive desire for new things and, in their investigation of the mystery of our redemption boldly dare to go beyond the sacred and inviolable limits [of true doctrine], should ponder this definition more truly and more deeply. Finally, let all those who bear the Catholic name draw from it strong encouragement; let them hold fast this evangelical pearl of great price; let them profess and hold it with unadulterated faith; let them render it due honor inwardly and outwardly; and - what is still more important - let them pay it the tribute of lives in which, through God's mercy, they shun whatever is unworthy, incongruous or blameable, and in which they shine with the beauty of virtue, so that they may become sharers of this divinity, who deigned to be a partaker of our humanity.
Source: Sempiternus Rex Christus (Vatican.va)