Christ explained to St Catherine of Siena about the value of our finite acts.
Catherine was delighted to make of her life a reparation for sinners. One day she asked Our Lord could she offer some very severe penances in reparation for a particular person, to atone for his sins. Our Lord replied, “But Catherine, do you not know that all the penances you could offer during your entire lifetime would not be sufficient to atone for even one venial sin? An offence against the infinite majesty of God simply cannot be repaired by any mortal, however holy and virtuous. Yet, if you offer your prayers and penances in union with My Passion, they become attached to the infinite merit of My own Passion, and in this way you can truly make reparation. It is your love, not the value of the penance in itself, which is of value to Me.”
Another time He said to her, 'You owe absolutely everything to me, from your very existence onwards. Hence you cannot give Me anything. But that is why I give you your trials, and especially your troublesome neighbours. When your neighbour has done nothing at all to deserve your love, and yet you treat them with charity for My sake, I accept it, and in thie way you truly give Me a gift.'