St Paul tells us in the second reading today that
Whatever was written in the former days was written for our instruction, that by steadfastness and by the encouragement of the scriptures we might have hope.
The scriptures then give us hope, and Advent is precisely the time of hope, when we wait to celebrate the great mystery of the Incarnation.
Paul is referring in the first place to the Old Testament scriptures. At daily and Sunday Mass during Advent we join the patriarchs and prophets of the Old Testament in a pilgrimage towards God. A pilgrimage of understanding the beauty of the prophecies and insights these inspired seers received. By meditating on these prophecies we come to see how wonderfully and perfectly they are fulfilled by Jesus Christ.
Along with the book of Psalms, St Thomas Aquinas regarded the book of Isaiah as more like a gospel than a prophecy, so full and beautiful are its visions of the coming divine and human Messiah. Indeed, it is part of the belief of the New Testament that when Isaiah had his vision of the Lord in the Temple (Isaiah 6), it was truly a vision of the pre-incarnate Christ; as it says in John 12:41
Isaiah said this because he saw his glory and spoke of him.
Of course any vision of Christ, whether bodily or intellectual, or both, implies a certain awareness of the persons of the Father and the Spirit. In Isaiah's Temple vision this is provided by the Trinitarian hymn of the angels: the 'Holy, Holy, Holy.' This hymn, which is possibly the oldest part of the Mass, reminds us that we join in the worship of all the saints and angels in heaven, in their unending praise of the Trinity.
In today's prophecy Isaiah presents another vision of the Christ. This time he links him clearly with the person the Holy Spirit, and indeed, points to him as the giver of the Spirit, and of the Spirit's gifts. The Spirit of the Lord 'rests' upon the Messiah because the Messiah possesses the fullness of the Spirit, this fullness does not decrease or vary. This vision is parallel to another very early vision preserved in the Book of Revelation. At Rev 5:6 the Lamb as though slain, that is, the Messiah, is seen with seven horns and seven eyes. These represent the fullness of the gifts of the Spirit he gives to the world.
Thus the Messiah will be full of the Holy Spirit, and the gift of the Spirit will be connected with his death. John combines these two crucial doctrines, the death of the Messiah and gift of the Spirit, in his preaching. He hails Jesus as the 'Lamb of God' and in today's Gospel proclaims 'he will baptize you with the Holy Spirit and with fire.'
He clearly portrays both the sacred humanity and the divinity of the Messiah. He will be fully human with eyes to see and ears to hear; with a waist and loins which will be girt; but will exercise the divine prerogatives of judging the earth and slaying the wicked with spiritual power.
The future kingdom of the Messiah is described in the following verse; where the original justice and peace of the world will be restored, and raised to an even greater degree of harmony, 'for the earth will be full of the knowledge of the Lord.'
The mission of the Messiah to bring all peoples into friendship with God and each other is shown in verse ten: The nations will seek him as he will be raised as an ensign, or a signal, of salvation offered to everyone. Jesus refers to this when he says:
And I, when I am lifted up, will draw all men to myself.
The primary meaning of Christ as an ensign, then, is his death. In Isaiah 13:2 God says through the prophet
On a bare hill raise a signal, cry aloud to them, raise your hand.
This action prefaces the terrible 'day of the Lord.' This surely refers to the cross raised on the hill of Calvary, when Christ raised his hands on the wood and cried out 'It is accomplished!'
But God's generosity has given us more than one sign, however. In this season we have the sign of the star that lead the Magi to the infant Christ; we can also think of the Resurrection and Ascension which are signs to the whole world of the divinity and humanity of Christ. 'The Root of Jesse shall stand as an ensign to the people.'
The greatest sign in our everyday lives is, of course, the effective sign of the sacrifice of the Mass; here Jesus is truly present as a saving sign for us and for the whole world.