Response to the following:
What are the four marks of the church and how do they function in the church? If you are not Catholic find out how your Church defines the Church and describe the nature of the sacraments? Many churches have catechisms of sorts that describe their primary teachings.
Look up Ecclesis de Eucharistia and describe why that Eucharist is the source and summit of the life of the church. What does the Eucharist do for the Church? Why is it essentail to the Catholic understanding of the Church? What are the four marks of the Church and how are they understood in the light of the Eucharist?
Reference: www.papalencyclicals.net