Being faithful in our service to God means choosing to love him, and serve him, often times in the midst of circumstances where we do not have everything we want, or even need. Which includes not having everything present that we might want, in ourselves. We may work very hard to make up for our personal deficiencies, or what we perceive as weaknesses, without them ever improving.
Craig Barnes reflects,
And that hurts. It hurts not just because we [feel] it's what [others] want, but because it is what we want for ourselves.
Further, he quotes Pope Gregory the Great,
...Almighty God perfects in great measure the minds of those who [serve], but leaves them partially imperfect, for this reason,
that when they are resplendent with extraordinary attainments, they may grieve with disgust for their imperfections, and, least of all, exalt themselves for great things, when they have to labor and struggle against very small matters. And as they are not able to overcome the very little things, they should not presume to pride themselves on the great things they accomplish.
Do you see?
"God alone is whole and complete, lacking in nothing."