1. The spiritual espousals.2. The prayer of union resembles a betrothal.3. Before the spiritual nuptials temptations are dangerous.4. The great good done by souls faithful to these graces.5. Religious subject to the devil's deceptions.6. Satan's strata-gems.7. Why they are permitted.8. Prayer and watchfulness our safeguards.9. God's watchfulness over such souls.10. Progress in virtue.11. Insignificance of our actions compared with their reward.12. St. Teresa's motives for writing on prayer.
1. You appear anxious to know what has become of the little dove and where she obtains rest, since obviously she can find it neither in spiritual consolations nor in earthly pleasures but takes a higher flight. I cannot tell you until we come to the last mansion: God grant I may remember or have leisure to write it. It is nearly five months since I began this work, and as my head is too weak to read it again, no doubt it will be very disconnected and full of repetitions: however, as it is only for my sisters, that will matter little. Yet I should like to express myself more fully about the prayer of union and will make use, to the best of my scanty wits, of a comparison. Later on we will speak of the little butterfly, which is never still, for it can find no true repose, yet always fertile, doing good both to itself and others.  You have often heard that God spiritually espouses souls: may He be praised for His mercy in thus humbling Himself so utterly. Though but a homely comparison, yet I can find nothing better to express my meaning than the Sacrament of Matrimony although the two things are very different. In divine union everything is spiritual and far removed from anything corporal, all the joys our Lord gives and the mutual delight felt in it being celestial and very unlike human marriage, which it excels a thousand times. Here all is love united to love; its operations are more pure, refined, and sweet than can be described, though our Lord knows how to make the soul sensible of them.
2. I think this union does not attain as far as the spiritual espousals but resembles the preliminaries that take place when two people are contemplating a betrothal. Their suitability and willingness for the alliance are first discussed; then they may be allowed to see one another sometimes so as to come to a decision. Thus it is in the spiritual espousals: when the preliminary agreement has been made and the soul thoroughly understands what great advantages she will gain, having resolved to fulfil the will of her Spouse in all things and to do all she can to please Him, His Majesty Who knows well whether this is so in reality, wishes in return to gratify His bride. He therefore bestows this favour upon her, visits her and draws her into His presence, as He wishes her to know Him better. We might compare the prayer of union to a visit, for it lasts but a very little while.  There is no longer any question of deliberation, but the soul in a secret manner sees to what a Bridegroom it is betrothed; the senses and faculties could not, in a thousand years, gain the knowledge thus imparted in a very short time. The Spouse, being Who He is, leaves the soul far more deserving of completing the espousals, as we may call them; the enamoured soul in its love for Him makes every effort to prevent their being frustrated. Should it grow neglectful and set its affections on anything except our Lord, it will forfeit everything: this loss is as great as are the favours the soul has continually received, which are precious beyond description. 
3. O Christian souls! you whom God has brought thus far! I implore you for His dear sake not to grow careless, but to avoid all occasions of sin; you are not strong enough yet to undergo temptation, as you will be after the espousals which take place in the next mansion. Here the betrothed are, as they say, only acquainted by sight,  and the devil will spare no pains to oppose and prevent their nuptials. Afterwards, when he sees the Bride is wholly given to her Bridegroom, he is afraid to interfere, having learnt by experience that if he molests her, while he loses much, she will gain greatly in merit.
4. I can assure you, my daughters,  that I have known people far advanced in the spiritual life who had reached this state of prayer yet whom the devil reclaimed by his subtlety and wiles: as I have often said, all hell leagues together against such souls because the loss of one of them entails the perdition of many more, as Satan is well aware. If we considered how many men God draws to Himself by means of one, we should praise Him fervently. Think of the multitudes converted by the martyrs or by one young maiden like St. Ursula! Again, of how many victims the evil one was deprived by St. Dominic, St. Francis, and other founders of religious orders. How many more he loses, even now, through Father Ignatius [Loyola], who founded the Company [of Jesus]! As we read their lives, we learn that they received such graces from God. How was this great good done except by their efforts not to forfeit, through any fault of theirs, these divine espousals? Oh, my daughters, how willing our Lord is to grant us the same graces! In fact, there is even more urgent need now for persons to prepare for such favours, since there are fewer who care for His honour. We love ourselves too much and are too prudent to give up any of our rights. What a deception! May God in His mercy give us light, lest we sink into such darkness.
5. You may question or be in doubt on two points. Firstly: if the soul is entirely united with the will of God, as I have stated, how can it be deceived, since it ever seeks to follow His pleasure? Secondly, how can the devil enter and work such havoc as to destroy your soul while you are so utterly withdrawn from the world and constantly frequent the Sacraments?  At the same time you enjoy the society of angels (as we might call them) and by the mercy of God you desire nothing but to serve and please Him in all things?  It is not surprising that people in the world should run such risks. I admit you have the right to say this, for God has shown us signal mercy; but, as I said above, knowing as I do that Judas was amongst the Apostles and that he held constant intercourse with God Himself, to Whose words he listened, I learn that the state of religion does not make us safe.
6. To your first question I reply that doubtless if such a soul is always faithful to the will of God, it cannot be lost; the evil one, however, comes with his keen subtlety and, under the pretext of good, leads it astray in some trivial matter and causes it to commit small defects which he makes it believe are harmless. Thus, little by little, the reason is obscured and the will is weakened while the devil fosters his victim's self-love, until, by degrees, he succeeds in withdrawing it from union with the will of God and makes it follow its own will.
7. The answer to your first inquiry will serve for the second. No enclosure can be too strict for Satan to enter nor any desert too remote for him to visit. Besides, God may permit him to tempt the soul to prove its virtue; for as He intends it to enlighten others, it is better for it to fail in the beginning than when it might do them great harm.
8. We must beg God constantly in our prayers to uphold us by His hand; we should keep ever in our minds the truth that if He leaves us, most certainly we shall fall at once into the abyss, for we must never be so foolish as to trust in ourselves. After this I think the greatest safeguard is to be very careful and to watch how we advance in virtue; we must notice whether we are making progress or falling back in it, especially as regards the love of our neighbour, the desire to be thought the least of all and how we perform our ordinary, everyday duties. If we attend to this and beg Our Lord to enlighten us, we shall at once perceive our gain or loss.
9. Do not suppose that after advancing the soul to such a state God abandons it so easily that it is light work for the devil to regain it. When His Majesty sees it leaving Him, He feels the loss so keenly that He gives it in many a way a thousand secret warnings which reveal to it the hidden danger. 
10. In conclusion, let us strive to make constant progress: we ought to feel great alarm if we do not find ourselves advancing, for without doubt the evil one must be planning to injure us in some way; it is impossible for a soul that has come to this state not to go still farther, for love is never idle. Therefore it is a very bad sign when one comes to a stand-still in virtue. She who aspires to become the spouse of God Himself, and has treated with His Majesty and come to such an understanding with Him, must not leave off and go to sleep. 
11. To show you, my daughters, how Christ treats the souls He takes for His brides, I will now speak of the sixth mansions. You will then see how little in comparison is all that we can do or suffer in His service to prepare ourselves for the reception of such immense favours. Perhaps our Lord decreed that I should write this in order that the knowledge of the great reward to come, and of His infinite mercy in seeking to give and to manifest Himself to such worms as we are, might make us forget our wretched, petty, earthly pleasures and run on our way with eyes fixed on His grandeur, inflamed with love for Him.
12. May He enable me to explain some of these difficult matters; if our Lord and the Holy Ghost do not guide my pen, I know the task will prove impossible.1 beg Him to prevent my saying anything unless it will profit you. His Majesty knows that, as far as I can judge, I have no other wish but that His Name may be glorified and that we may strive to serve a Lord Who thus recompenses our efforts even in this world. What, then, will be our joy in heaven where it will be continuous, without the interruptions, labours, and dangers of this tempestuous sea of life? Were it not for the fear of losing or offending Him, we should wish to live until the end of the world  in order to work for so great a God -- our Lord and our Spouse. May His Majesty enable us to render Him some service free from the many faults we always commit, even in good works! Amen.
 Compare: habebit fructum in respectione animarum sanctarum' (Breviar. Rom. Ant. ad Laudes de Com. Virg.); quasi apis argumentosa Domino deservisti' (Ibid. Feast of St. Cæcilia.)  Life, ch. xviii.  Way of Perf. ch. xxxi. 10.  Phil. a SS. Trinit. l.c. p. iii. tract. i. disc. ii.[art. 2.  Contrast with this paragraph what the Saint says in her Life, ch. xix. 8.  Life, ch, xxxvi. 26; xxxix. 14. Found. ch. i. 1-4.  Way of Perf. ch. i, 2; xiii. 3. Found. ch. i. 3.  Life, ch. xix. 9.  Life, ch. xix. 7.  Rel. ix. 19.
 Life, ch. xviii.
 Way of Perf. ch. xxxi. 10.
 Phil. a SS. Trinit. l.c. p. iii. tract. i. disc. ii.[art. 2.
 Contrast with this paragraph what the Saint says in her Life, ch. xix. 8.
 Life, ch, xxxvi. 26; xxxix. 14. Found. ch. i. 1-4.
 Way of Perf. ch. i, 2; xiii. 3. Found. ch. i. 3.
 Life, ch. xix. 9.
 Life, ch. xix. 7.
 Rel. ix. 19.