Yesterday, I spent time meditating on the title Life as it pertains to Christ the Tree of Life; however, St. Ambrose highlights the title in order to show how it applies to the Holy Spirit. In chapter three of the second book of his treatise On the Holy Spirit he observes:
So, then, the world had not eternal life, because it had not received the Spirit; for where the Spirit is, there is eternal life
Again, because today we are on the Eve of Christmas, let me try to bring this idea to bear upon the Nativity. Yesterday, I noted how the hymnody equated the Incarnation with salvation due to the reality of God becoming a human being and therefore shattering that which separates us from God, as we sing in the Stichera of Vespers for the Nativity:
Come, let us rejoice in the Lord as we declare this present mystery. The middle wall of partition is broken asunder; the flaming sword is turned back, the Cherubim withdraw from the Tree of Life, and I partake of the Paradise of Delight, whence I was cast out before through disobedience.
However, the Tree of Life is also the Cross, therefore more is yet to be done. Note all of the things accomplished by Christ in this prayer from the Anaphora of the Liturgy of St. John Chrysostom:
Remembering, therefore, this command of the Savior, and all that came to pass for our sake, the cross, the tomb, the resurrection on the third day, the ascension into heaven, the enthronement at the right hand of the Father, and the second, glorious coming.
All of this is necessary in order for what happens next in the Divine Liturgy:
Once again we offer to You this spiritual worship without the shedding of blood, and we ask, pray, and entreat You: send down Your Holy Spirit upon us and upon these gifts here presented.
And make this bread the precious Body of Your Christ.
And that which is in this cup the precious Blood of Your Christ.
Changing them by Your Holy Spirit.
In other words, our access to Christ, the Tree of Life, is through the descent of the Holy Spirit. Without that descent, there is no Incarnaton, no cross, no tomb, no resurrection, no ascension, no enthronement and no second coming. And without any of these, that descent is not accomplished in us.
Remember this the next time we pray Psalm 50(51):
Do not cast me out of your presence: do not take your Holy Spirit from me.