I think that one of the legacies of the Ad Gentes document is the idea that the missionary zeal which motivated the document is something still needed in the expansion of modern Christianity. The reading of the document is one in which the pressing need is to develop the framework for greater missionary work in both numbers and effectiveness. The mission to bringing the teachings of Christ to more people is something that is embedded in the document and represents its legacy today. When recently speaking to the College of Cardinals, Archbishop Dolan spoke to this idea, a profound legacy of the Ad Gentes decree:
It is as old as the final mandate of Jesus, “Go, teach all nations!,” yet as fresh as God’s Holy Word proclaimed at our own Mass this morning. I speak of the sacred duty of evangelization. It is “ever ancient, ever new.” The how of it, the when of it, the where of it, may change, but the charge remains constant, as does the message and inspiration, “Jesus Christ, the same yesterday, today, and tomorrow.”
The need to "teach all nations" is something that remains in the Ad Gentes' reach to the modern setting. It is one in which the Church recognizes that the fulfilment of a critical teaching of Jesus can only be done when there is both an individual and institutional emphasis on spreading the word. The Ad Gentes decree in the 1960's speaks to a condition that is still present today, and thus its legacy is seen in the same calls to action both then and now.