Presumptuousness

There is a great presumptuousness in saying that you are not the right one to perform a certain act of service for Hashem, because of your great distance from Him, in comparison with your friends. You must never make these kinds of excuses before Hashem. Man is not his own judge. Who really knows what his true position is before Hashem, or where his actions might take him? Every person is an individual in his own right. No one can be compared to anyone else.

(Reb Nosson of Breslov)