The main religious purpose of all Christians is the worship of – in other words, showing honour and reverence to – God. Worship in this sense is not specifically Christian. It is to be found in all religions. The form it takes naturally varies from religion to religion, but within Christianity most Churches have rather similar forms of public worship. This public worship is called ‘the liturgy’, and it comes from two Greek words meaning ‘public’ and ‘work’. The ‘liturgy’, then, is something done in public, and is a corporate act – that is to say, it is (usually) not done by individuals on their own. One has to use the word ‘usually’ here because in many Churches, certainly the Anglican and Catholic Churches, the liturgy is in a sense prescribed, and some think it should take place whether or not there is anyone present – apart, obviously, from the person carrying out, or presiding at, the liturgy, who is known as ‘the celebrant’.