The Archbishop of Canterbury has used his first Christmas Day sermon to highlight the "injustices" facing Britain's poor and victims of conflicts around the world.
The Most Rev Justin Welby called on Christians to "challenge the causes of poverty" despite signs of an economic recovery in the UK, as he addressed the congregation at Canterbury Cathedral.
Archbishop Welby, who was enthroned as leader of the 77 million-strong Anglican community in March, said Christian communities in the Middle East were being "attacked and massacred" and he condemned the continuing suffering in Palestine, Israel and South Sudan.
Earlier on Christmas morning, a car bomb near a church in Baghdad killed at least 15 people - thought to be mainly Iraqi Christians.
"Today, singing of Bethlehem, we see injustices in Palestine and Israel, where land is taken or rockets are fired, and the innocent suffer," he said.
"We see injustice in the ever more seriously threatened Christian communities of the Middle East.
"They are attacked and massacred, driven into exile from a region in which their presence has always been essential.
"We see terrible news in South Sudan, where political ambitions have led towards ethnic conflict. On Saturday I was speaking to a bishop under siege, in a compound full of the dying.
"We see injustices at home.
"Even in a recovering economy, Christians, the servants of a vulnerable and poor saviour, need to act to serve and love the poor; they need also to challenge the causes of poverty."
Welby, who launched a crusade against payday lenders earlier this year, cited a poll in Prospect magazine which suggested the church is more trusted on politics than religion, adding: "The two cannot be separated.
"Christ's birth is not politics, it is love expressed.
"Our response is not political, but love delivered in hope. The action of the churches in the last five years is extraordinary, reaching out in ways not seen since 1945.
"Yet no society can be content where misery and want exist, unless through our love collectively we also challenge the greed and selfishness behind it."
The Archbishop admitted "it will always be an untidy church because we are in a vulnerable, untidy, broken world".
"Yet when we see the fact of Christ's birth, hear the witnesses, receive the life he gives and respond in passionate discipleship, then all our vulnerabilities, muddles and weaknesses are carried in His strength.
"The Christian meaning of Christmas is unconditional love received, love overflowing into a frequently love-lost world."
The Archbishop, who has more than 48,000 followers on Twitter, posted a Christmas video message yesterday on the photo-sharing website Instagram.
In the message, he said: "Christmas means that, through Jesus, God shows unconditionally that he loves us. I pray that he gives you a very blessed Christmas."