In order to counter this "integral catechesis" is needed, through which the faithful can teach Christianity "which truly involves our entire existence and which makes us credible witnesses of Jesus Christ, truly God and truly man". That was the objective which Saint Cyril of Jerusalem aimed to achieve in the IV century but which is still valid today, and which was also at the heart of the Pope's reflection during his general audience today, centred on the figures of the early Church and the relevant aspects of their teachings in today's world. Cyril of Jerusalem, a fundamental figure above all for his catechesis, was the early father of the Church to whom Benedict XVI dedicated his one hundredth general audience of his pontificate. The over 10 thousand people, who took part in the audience, where spared the June heat and divided between St. Peter's basilica and the Paul VI audience hall. The Pope recalled that Cyril bishop of Jerusalem in the IV century, "against his will", was involved in the "controversies" of the Eastern Church, but the Pope particularly underlined his work as a teacher of the faith, author of 24 catechesis, a true "introduction to Christianity" and "still today model of the journey to being Christian". Cyril, unjustly accused of Aryanism, while he was instead "a man full of faith", met with exile three times before he was allowed to return for good to Jerusalem in 378 "bringing peace and unity once again among the faithful". His catechesis was not only intellectual but "a journey of learning how to live in the Christian community" and his teaching is "an integral catechesis which involves the body, soul and spirit, an emblem even for the Christians of today". In short in his teaching "doctrine and life are not two distinct entities but one existential journey". The objective which we must attempt to reach even today remains: "learning a Christianity that really involves our entire existence". At the end of his audience, greeting the diverse groups present the Pope reaffirmed his stance on the subject of stem cell research: "the position of the church is clear and supported from science and reason – that scientific research is promoted and encouraged, as long as it does not cause the destruction of human beings, whose dignity is inviolable from the first moment of existence