Moroni 10:25

And wo be unto the children of men if this be the case; for there shall be none that doeth good among you, no not one. For if there be one among you that doeth good, he shall work by the power and gifts of God.

Moroni wrote earlier that all good comes from God. Therefore, if anyone does anything truly good, he does it through God's grace, which are the gifts of the Spirit. The glory thus belongs to God. The definition, then, of a good work is something we do for God. The Savior scolded the hypocrites of his day for putting on a pious show of good for their own gain. True, they gave to the poor and prayed regularly, but they did these things for the wrong reasons. Therefore, they were not truly good works. They may have been helpful, but they were not good. According to Jesus, the widow who contributed two mites did more good than the rich man who donated a large sum, for she gave all she had to God, while the rich man kept most of his fortune for himself. If anyone does real good, it is because he or she has one goal in mind, which is to serve God with the gifts he has given them.

Moroni 9:6

And now, my beloved son, notwithstanding their hardness, let us labor diligently; for if we should cease to labor, we should be brought under condemnation; for we have a labor to perform whilst in this tabernacle of clay, that we may conquer the enemy of all righteousness, and rest our souls in the kingdom of God.

Our calling is to labor to the end. The outcome is in the Lord's hands. We count our success in sharing the gospel not by the number of converts, but by our faithfulness in the work. In the eyes of the Lord, a missionary who works diligently and tirelessly every day is as successful as one who baptizes hundreds. God is far more impressed with intent and effort than with numbers. The same is also true in the work we do in our families. We must labor to the end with our family, regardless of how unpromising the results may appear. God labors with each of us to the very last day. He expects us to do the same with each other.

3 Nephi 18:29

For whoso eateth and drinketh my flesh and blood unworthily eateth and drinketh damnation to his soul; therefore if ye know that a man is unworthy to eat and drink of my flesh and blood ye shall forbid him.

Let's be clear: no one is worthy to partake of the sacrament. We come to the sacrament table in introspection and repentance, acknowledging that we failed to keep our covenants perfectly during the preceding week. We renew our covenants of the sacrament weekly because weekly we fall short of our desires to be faithful and righteous. Therefore, to partake worthily does not mean to be without sin but to be without hypocrisy. We partake worthily when we truly want to keep the covenants we make and are willing to strive to be obedient. The point of the sacrament is not to be perfect but to have the intent to become perfect through the continuous atonement of Christ.  Jesus warns his disciples about those who partake of the sacrament for show or to be socially acceptable or to hide rebellion and intentional sins. For such, the sacrament is a curse rather than a blessing. If one does not intend to keep the covenants, it is best that he not pretend to make them in the first place. For the rest of us, we just have to keep trying.