They described the role as "pivotal".
Each catechesis session will be led by one of 300 bishops from around the world.
WYD Evangelisation director Steve Lawrence says catechesis is a chance for pilgrims to learn more about their faith, discuss issues with clergy, and gain further spiritual guidance.
He said: "The ultimate goal of Catechesis is to guide, with the help of the Holy Spirit, the minds and hearts of the pilgrims."
Catechists (WYD Media Release, 26/8/07)
LINKS (not necessarily endorsed by Church Resources)
World Youth Day 2008
World Youth Day Catechesis
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