The fact that the Orthodox Church has preserved the original teaching in purity and flawlessness is acknowledged by many – even among those who do not belong to the Church. However, they add at the same time that (supposedly) the Orthodox Church does not reveal its righteousness and truthfulness in any way, that it does not attract anybody to itself, that it does not grow and succeed on earth; that having set a goal of preserving the original teaching, the Orthodox Church has become introverted, secluding itself from everything else, coming to a standstill at the freezing-point; that life has come to a halt in it; that indeed it has become a lifeless church. At the least, some say, it does not possess the most important sign of vitality – namely, the spirit of missionary activity.
Perhaps it is true that the life of the Orthodox Church does not catch the eye as much and does not shine with so many bright colors as the life of other church communities, where there is more noise and luster, but where in return there are fewer innermost fruits of the Spirit of God. In particular, it is true that we do not have such widely organized missionary establishments – such “congregations” and “advancements of faith” – as the communities of other confessions have; and we do not spend as much money on this pursuit as they do. But nevertheless, the Orthodox Church remembers Christ’s commandment to spread the evangelistic message, and the spirit of missionary activity is not at all foreign to Her – only, Her missionary work has a different character...
But the most important fact is that the Orthodox Church conducts Her missionary work quietly, with humility and reverence, being conscious of the powerlessness of man and the strength of God. Missionaries of other confessions often do not mind to make noise, to make a din about their work. They meticulously record their heroic deeds so that the whole world might know of their actions and glorify them, and it is for this reason that they are much spoken about.
But the Orthodox messengers of the Good News act differently. They undertake their holy endeavor not to gain glory for themselves from people, but to receive the mercy of God for themselves and salvation for others. They do not trumpet their own successes before the world, and they attribute them not to themselves but to the might of God.
Excerpts from St. Tikhon of Moscow: Instructions & Teachings For the American Orthodox Faithful