The Pope has called on world leaders to work together to resolve the conflicts in the Middle East. At the Synod on the Family in Rome, he urged all 270 bishops and cardinals to pray for peace and reconciliation. He also condemned "relativism", warning it was a temptation of the devil.

Opening the fourth day of the synod this morning, Pope Francis said: "We are painfully affected and we follow with great concern what is happening in Syria, in Iraq, in Jerusalem and the West Bank, where we see an escalation of violence involving innocent civilians and continues to fuel a humanitarian crisis of enormous proportions. War brings destruction and multiplies the suffering of the people."

He urged the international community to "use the instruments of international law, diplomacy, to resolve the current conflicts."

He also offered prayers for those parts of Africa in conflict. 

Earlier, in his homily at the daily Mass in his Vatican home, Casa Santa Marta, he warned against the ability of the devil to "anaesthetise" a person's conscience.

He said: "The Evil One is hidden. He comes with his very educated friends, knocks at the door, asks for permission, comes in, and lives with that person. Drop by drop, he gives him instructions on how to do things with relativism."

The devil attacked by steps to "anaesthetise the conscience". Pope Francis said: "This is a great evil. When the Evil Spirit succeeds in anesthetising the conscience, it is then he can claim a true victory, for he has become the master of that conscience."

Watchfulness and discernment were the best guards against such attacks, he added.

Cardinals and bishops at the three-week synod have been given permission to put their three-minute interventions online. 

Cardinal Timothy Dolan of New York repeated traditional teaching that marriage can be between a man and a woman only and to "restore that noble nature of marriage and family as God intended" is the starting point for the synod, as well as its goal.

He admitted that pastoral realism meant the contemporary situation of marriage and family had to be considered. But the synod's duty was still "to follow Jesus in recalling and restoring what His Father intended."

Archbishop Charles Chaput of Philadelphia presented a particularly bleak picture of the modern life. "We human beings have wounded our oceans and the air we breathe. We've poisoned the human body with contraceptives. And we've scrambled the understanding of our own sexuality. In the name of individual fulfillment, we've busied ourselves with creating a new Babel of tyranny that feeds our desires but starves the soul."

He made it clear he would be opposing firmly any moves to relax the ban on communion after divorce and civil remarriage, as well as on contraception.

"We need to call people to perseverance in grace and to trust in the greatness God intended for them — not confirm them in their errors."