This connects with what precedes in this way. There he expressed that he loved them with strong love. Here he seems to explain: how could I fail to love you? Great is my boldness toward you.
Now I see that I can rely on you in everything. You have shown that you relate to me as disciples to a teacher, as children to a father.
This gives me courage for labor among you and for you. I know that it will not be useless.
“Great is my boasting about you.” You have given me many occasions to praise you and to boast of you. I have always boasted of you before others. Now you have increased my eagerness for this and have shown much that is praiseworthy beyond your former praiseworthy qualities.
“I am filled with consolation.” I was grieving, but as soon as Titus came and told me about you, the sorrow departed and I was filled with consolation.
“What consolation? The consolation he received from you. Having corrected yourselves, you comforted me by your deeds” (Saint Chrysostom).
“I overflow with joy.” “Again he reveals the warmth of his love for them. How insatiable it was! Even a small return of love from those whom we love brings great joy, because of our strong love for them.
“When speaking of consolation, he said, ‘I am filled,’ that is, I have received what was fitting. But when speaking of joy, he said, ‘I overflow.’ That is, I feared greatly for you, but you have fully satisfied and comforted me.
“You have not only removed from me the cause for sorrow, but have also brought me abundant joy. Declaring how great this joy is, he expresses it not only by saying, ‘I overflow with joy.’
“He also adds, ‘in all our affliction,’ epi pase. Such was the delight given to us that it was not darkened even by great sorrow. On the contrary, by the abundance of its greatness it overcame all our sorrows and does not allow us to feel them” (Saint Chrysostom).