In the human body, there are some essential functions, such as breathing and the beating of the heart.
I like to imagine that the personal and communal prayer of us Christians is the breath, the heartbeat of the Church, which instills its strength in the service of those who work, study, teach; which makes fruitful the knowledge of educated people and the humility of simple people; which gives hope to the tenacity of those who fight injustice.
Prayer is our saying "yes" to the Lord, to His love that reaches us; it is welcoming the Holy Spirit who, without ever growing weary, pours out love and life upon all.