In Jesus Christ's most famous sermon, he declared "Ye are the light of the world. A city that is set on an hill cannot be hid. Neither do men light a candle, and put it under a bushel, but on a candlestick; and it giveth light unto all that are in the house. Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven." (Matthew 5:14-16)
In the following chapter, Christ seems to completely withdraw this concept in favor of being secretive in doing good to avoid hypocrisy:
"Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven. Therefore when thou doest thine alms, do not sound a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward. But when thou doest alms, let not thy left hand know what thy right hand doeth: That thine alms may be in secret: and thy Father which seeth in secret himself shall reward thee openly. And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward. But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly. But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking. Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him." (Matthew 6:1-8)
These two concepts seem mutually exclusive. On the one hand, God wants people to openly stand for what is right by doing good publicly... on the other hand, God wants us to hide our good deeds to be rewarded for them, and to avoid being as the hypocrites are. How can Christians reconcile these two points?
These points seem especially important in the field of missionary work. Every Christian has a responsibility to witness for Christ. Consider the words in the New Testament: "But sanctify the Lord God in your hearts: and be ready always to give an answer to every man that asketh you a reason of the hope that is in you with meekness and fear: Having a good conscience; that, whereas they speak evil of you, as of evildoers, they may be ashamed that falsely accuse your good conversation in Christ." (1 Peter 3:15-16) Also, these words from the Book of Mormon that expound on the commitment made in baptism: "...and to stand as witnesses of God at all times and in all things, and in all places that ye may be in, even until death, that ye may be redeemed of God..." (Mosiah 18:9) Also, contemporarily, consider the words in the Doctrine and Covenants: "Behold, I sent you out to testify and warn the people, and it becometh every man who hath been warned to warn his neighbor." (D&C 88:81)
If Christians follow the advice of Paul to Timothy when he said "be thou an example of the believers, in word, in conversation, in charity, in spirit, in faith, in purity." (1 Timothy 4:12), how can we simultaneously heed the words of Christ to do good in secret?
More to the point, how can a Christian ask someone else to follow Christ when they themselves are guilty of not following him as well as they should? Did Christ not repeatedly and vehemently condemn such hypocrisy?
The answer is that he did condemn such hypocrisy. The Pharisees were frequently subjects of such condemnation. They openly prayed, gave alms, and fasted... which were all things that God had commanded. Christ pointed out that they paid tithes, but devoured widows' houses and tolerated swearing by altar, as long as they did not swear by the gifts on it. (Matthew 23)
Of course every person that encourages someone else to make correct choices except for Christ himself takes on a degree of the same hypocrisy that Christ condemned, because every other person is guilty of sin.
Fortunately, in the gospel of Jesus Christ, even hypocrites can be saved. Avoiding hypocrisy is not a valid excuse to put one's light under a bushel.
Consider the parable of the talents. (Matthew 25) The servant that had received one talent hid it in the ground for fear of losing it. When the Lord returned, he was displeased with the servant. He had not given that servant a talent to be buried away... but to be used. I suggest that the talent is symbolic of many things, and that one of them is knowledge of the gospel of Jesus Christ. The word gospel means good news... and news is meant to be spread, not to be buried or hoarded away.
Additionally, Christ declared that the greatest commandments were to love God and to love our neighbors as ourselves. (Matthew 22:37-40) When we arrive at the judgment bar of Jesus Christ, can anyone imagine that he would be pleased with those who refuse to share the message that cost his life and the lives of his Apostles? Can anyone suppose that a valid excuse for withholding knowledge that could bring peace, hope, and joy from others would be "I wanted to avoid being hypocritical"?
I do not believe that God wants people to wait until they have eliminated every flaw before they share the basics of the gospel of Jesus Christ with others. Of course, in connection with sharing the message that Jesus has power to save everyone, Christians are obligated to do all they can to eliminate those aspects of their thoughts, words, and deeds that are unchristian, but fulfilling the obligation is not prerequisite to sharing the message.
Furthermore, sharing the message of Christ does not require a Christian to loudly pray in restaurants or malls, or to announce their charitable contributions, or to babble in tongues before large audiences, or even divulging every personal spiritual experience. There are some experiences that are intended to emphasize the personal connection between an individual and God. Christ's power is not extended to the children of men to make them look good... it is extended to save them all.
The thing of which a Christian can be sure though, is that every person that they will ever meet has need of faith, penitence, and ordinances as prescribed by God. The thing of which a Christian cannot be sure is whether others already know this, or whether they may need some encouragement. Whether offered by men or God, it is a divine effort to make bad men good, and good men better.