464 During a meditation on humility, an old doubt returned:

that a soul as miserable as mine could not carry out the task which the Lord was demanding [of me]. Just as I was analyzing this doubt, the priest who was conducting the retreat interrupted his train of thought and spoke about the very thing I was having doubts about; namely, that God usually chooses the weakest and simplest souls as tools for His greatest works; that we can see that this is an undeniable truth when we look at the men He chose to be His apostles; or again, when we look at the history of the Church and see what great works were done by souls that were the least capable of accomplishing them; for it is just in this way that God's works are revealed for what they are, the works of God. When my doubt had completely disappeared, the priest resumed his conference on humility.