Orthodoxy believes that the Christian Faith and the Church are inseparable. It is impossible to know Christ, to share in the life of the Holy Trinity, or to be considered a Christian apart from the Church. It is in the Church that the Christian Faith is proclaimed and maintained. It is through the Church that an individual is nurtured in the Faith. At the centre of worship and belief is the Eucharist surrounded by the Divine Offices or the Cycle of Prayer. These prayers are sung particularly at Sunset and Dawn and at certain other times during the day and night. The Jesus Prayer is a sentence which is repeated many times; for example: "Lord Jesus Christ, Son of God, have mercy on me, a sinner." The aim of this repetition is to enable the person to concentrate solely on God. As in many Western churches, the Eucharist is a service consisting, in the first part, of hymns, prayers, and readings from the New Testament, and in the second the solemn offering and consecration of leavened bread and wine mixed with water, followed by the reception of Holy Communion. They believe in the doctrine of the Real Presence during Holy Communion – the belief that the consecration the bread and wine truly changes them into the Body and Blood of Christ.This belief holds that, through the power of the Holy Spirit, the essence (or substance) of the consecrated bread and wine transforms into the essence of the body and blood of Jesus during the Eucharistic prayer. This is called transubstantiation. Icons are of great importance to Orthodox Christians. These beautiful and elaborate paintings are described as "windows into the kingdom of God". They are used in worship both in the decoration of the church and for private homes. The icon is seen as both a form of prayer and a means to prayer.