How this prayer they call union comes about and what it is, I don’t know how to explain. These matters are expounded in mystical theology; I wouldn’t know the proper vocabulary. […] O my Jesus! What a sight it is when You through Your mercy return to offer Your hand and raise up a soul that has fallen in sin after having reached this stage! […] Here it becomes a devotee of the Queen of heaven so that she might appease You; here it invokes the help of the saints that fell after having been called by You.
Saint Teresa of Avila
The Book of Her Life, Cf. chap. 18, n. 2 and chap. 19, n. 5
Always referring to herself as a “wretched” sinner, St Teresa was speaking from personal experience when she writes of Jesus offering his hand to “raise up a soul that has fallen in sin” after having reached the stage of union, the fourth degree of prayer that she discusses in her autobiography. You can read more of St. Teresa’s quote about devotion to the Queen of Heaven here.