The elder warned us not to pray while our hearts were steeped in unprayerful feelings, without thoughts wandering as they chose. Prayer is not a mechanical activity, but a confrontation, a conversation with the Holy Presence. Pray humbly, then, in awe of God.
It is necessary that we find God, who cannot be found in noise and unpeace. God is the friend of silence. See how Nature -- trees, flowers, and grass -- grow in stillness; how stars, moon, and sun run their course in silence. The more we receive through quiet prayer, the more we can give in the activity of our daily lives. In essence, it is not what WE say, but what GOD says to us and through us. All our words are useless if they do not come from within.