Why The Church?
The first Christians said that the world was created for the sake of the Church, because the word "church" means the people God calls and gathers together in Jesus Christ to praise him and receive his blessings. They understood that you cannot belong to Jesus without belonging to his Church.
His mission is to everyone in all times and places. That is why he chose the twelve Apostles as the foundation of his universal (Catholic) Church. He sent them out to proclaim the Good News and to baptize all the nations. He promised to be with them until the end of time and he gave them his own power to forgive sins and heal the sick. He gave them his continuing presence and sacrifice in the Holy Eucharist. The members of the Church are so closely bound to Jesus through the sacraments that the Church is called the "Body of Christ".
The Church is God's 'ecosystem' for us, his way of giving divine life to human beings by the power of his Holy Spirit through the risen Jesus who is head of the Body. The Church is made up of the saints who are with him already in heaven, people who have died in Christ but whose souls are still being purified (Purgatory) until they are ready for heaven, and the people of God on earth, who may be sinners as well as saints.