The pair were speaking at an evening service in Rome commemorating decades of ecumenicalism between the Church of England and Roman Catholic Church.
The celebrations included highlighting 50 years since the opening of the Anglican Centre in Rome, a place where Catholics and Anglicans discuss and study theology, pray, minister and socialise together.
In the last 50 years the two churches have come to agree on several issues including baptism, Communion, how to use the Bible and mission and evangelism.
However the two church leaders admitted there were still "serious obstacles" and they "do not yet see" a way forward on other key theological issues, for example the role of women in church ministry and issues surrounding sexuality.
Despite differences the pair spoke of a "common faith" and a "common baptism", referring to believers in each other's churches as "brothers and sisters".
