Why did Jesus Christ found the Church? Jesus Christ founded the Church to bring all men to eternal salvation.
My sheep hear my voice, and I know them and they follow me. And I give them everlasting life; and they shall never perish, neither shall anyone snatch them out of my hand. (John 10:27-28)
How is the Church enabled to lead men to salvation? The Church is enabled to lead men to salvation by the indwelling of the Holy Ghost, who gives it life.
Further reading: CCC 763-766