The temple of God is a house of prayer. Everything in it must therefore be imbued with reverence, suffused with the spirit of heartfelt prayer. Whatever interferes with prayer must be kept away from the church.
There are, of course, countless things that interfere with and distract us from prayer, and there is no need to enumerate them, for our conscience should prompt us to know how to behave properly in church. Nevertheless, a reminder of some principal rules of church etiquette is sometimes needed, for we are not immune to the deteriorating standards of behavior in our society, and what was not so long ago a matter of course and of habit, is now a matter for instruction.
One must not talk in church, Such is the precept enjoined by the saints. All extraneous conversation, even when services are not in progress, is an offense to the sanctity of the Temple. For this reason, if it is necessary to talk during the service, and this cannot be postponed, it is better to leave the church. If one must give an instruction or ask a question, this should be done in a whisper and as briefly as possible.
One must likewise avoid disturbing those praying by walking from place to place, by coughing loudly, by jangling keys or coins in one's pocket, etc. All of this is not difficult to avoid if one is willing to make the effort. Greeting one another, shaking hands -- this also has no place in church. It can be done after the service.
One must also refrain from dressing immodestly or in a way that draws attention. This includes wearing make-up and perfume. After all, it is not in the name of God that this is done; it is not for the sake of prayer, but for the sake of what is even sinful to think about in the house of God.
Orthodox people have always cared for the beauty and adornment of their churches. In God's eyes, however, the most precious adornment of a church is a reverent stillness and ardent prayer. This should be our chief concern, for the Holy Church prays only for those who enter the temple with faith, reverence and the fear of God.