The plea was made in an Presidential Address by the Bishop of Swansea and Brecon John Davies (pictured) to members of the Church's Governing Body.
During the two-day summit at Cardiff City Hall this weekend, Bishop John said: "We must want and prepare our church to reach our centenary having really got to grips with re-imagining and refreshing our faith, our own knowledge of scripture, our understanding of our own discipleship and our potential to evangelise others.
"We need to become, afresh, a Jesus movement. But - and this is a big 'but' - we have to begin with ourselves, we have to re-evangelise our life - because unless we really know what we are about, unless we really are fit for purpose, there is little point in trying to reach out to others and to invite them in."
Speaking before a presentation from 18 young people from churches across Wales at the summit, Bishop John challenged the Church to "listen" to youth within the Church.
He also said: "We have to recognise that, while many young people apparently find both Jesus of Nazareth and the Gospel message of love, justice and inclusivity immensely attractive and inspirational, they often don't find the church to be a place where these are readily and engagingly encountered."
Also featuring on the agenda, will be a review of Church in Wales cathedrals and a proposed amendment to the Church's constitution.