St. Teresa of Avila and St. Thérèse of Lisieux were named Doctors of the Church after the Second Vatican Council. The two Carmelite nuns took their among men so unlike them.  St. Ambrose, St. Augustine, St. Athanasius, St. Basil,  were public figures who produced an enormous body of homiletic and theological works in their lifetime. The two women were nuns in a cloister; their few works circulated publicly only after their death.

Doctor is a title implying extensive knowledge. A doctorate in theology, for example, comes after extensive study in an accredited university and an approved thesis writing on some theological subject. I imagine if we asked Teresa of Avila about a theological question in her lifetime she would tell us ask one of the learned priests she knew. The two women were not theologians. 

 Why, then, are they called Doctors of the Church? Perhaps the account in Luke’s gospel of the seventy two disciples whom Jesus sent out and his prayer at their return may help us with an answer: 

 “I give you praise, Father, Lord of heaven and earth, for although you have hidden these things from the wise and the learned you have revealed them to the childlike… No one knows who the Son is except the Father, and who the Father is except the Son and anyone to whom the Son wishes to reveal him.”   Turning to the disciples in private he said,“Blessed are the eyes that see what you see. For I say to you, many prophets and kings desired to see what you see, but did not see it, And to hear what you hear and did not hear it. “ (Luke 19 21ff)

The seventy two disciples knew what prophets and kings –people well versed in religious and secular knowledge– did not know. They knew Jesus Christ; they saw and heard him. They had an immediate knowledge of Jesus Christ who reveals a loving God present in this world to bring it salvation.

That’s the knowledge Teresa of Avila and Thérèse of Lisieux  had. They were experts in that knowledge. They knew Jesus Christ and through him they knew that God is a loving God who loves us all and is with us all. They had an immediate knowledge of him, and they teach us to know him in prayer and in the ordinary circumstances of life.

That message is also in the documents of Vatican II, particularly in its Constitution on Divine Revelation. “In his goodness and wisdom God chose to reveal himself and to make known to us the hidden purpose of His will…The invisible God out of an abundant love speaks to us as friends and lives among us, so that He may invite and take us into fellowship with Himself.” 

The Second Vatican Council shifted the church from a notion that God reveals himself through divine truths and a revelation based on propositions to a revelation predominantly based on a personal revelation of God to us.  “The shift is from a predominantly propositionalist notion of divine truth and revelation to a personalist notion of divine truth and revelation.”( Ormond Rush. The Vision of Vatican II: Its Fundamental Principles (pp. 39-40). Liturgical Press. Kindle Edition.) 

Mystics like Teresa and Thérèse of Lisieux  teach this. In one sense, they’re more important than all the theologians usually credited for the council. They’re Doctors of the Church. 

If Christ Jesus dwells in one of us as his friend and noble leader, we can endure all things, for Christ helps and strengthens us and never abandons us. He is a true friend. And I clearly see that if we expect to please him and receive an abundance of his graces, God desires that these graces must come to us from the hands of Christ, through his most sacred humanity, in which God takes delight.

  Many, many times I have perceived this through experience. The Lord has told it to me. I have definitely seen that we must enter by this gate if we wish his Sovereign Majesty to reveal to us great and hidden mysteries. A person should desire no other path, even if he is at the summit of contemplation; on this road he walks safely. All blessings come to us through our Lord. He will teach us, for in beholding his life we find that he is the best example.

  What more do we desire from such a good friend at our side? Unlike our friends in the world, he will never abandon us when we are troubled or distressed. Blessed is the one who truly loves him and always keeps him near. Let us consider the glorious Saint Paul: it seems that no other name fell from his lips than that of Jesus, because the name of Jesus was fixed and embedded in his heart. Once I had come to understand this truth, I carefully considered the lives of some of the saints, the great contemplatives, and found that they took no other path: Francis, Anthony of Padua, Bernard, Catherine of Siena. A person must walk along this path in freedom, placing himself in God’s hands. If God should desire to r to the position of one who is an intimate and shares his secrets, we ought to accept this gladly.

  Whenever we think of Christ we should recall the love that led him to bestow on us so many graces and favours, and also the great love God showed in giving us in Christ a pledge of his love; for love calls for love in return. Let us strive to keep this always before our eyes and to rouse ourselves to love him. For if at some time the Lord should grant us the grace of impressing his love on our hearts, all will become easy for us and we shall accomplish great things quickly and without effort.