The Ukrainian Catholic Archeparchy of Philadelphia produced the above video of members of the faithful answering the titular question "Why I Come to Church".
As one girl said in the video, we go to Church because we are looking for answers. If we already knew everything and were already perfect, we wouldn't need Church. The Church is a hospital for sinners and nothing more. The Church's only mission is to convert all nations. We exist to help people out of sinful and Godless lives and into the love with which God loved them before He created them. We neither condemn nor condone; we convert. That is all for which we were established.
Why do I go to Church? Because that is where I can encounter Divine Love, far more clearly than anywhere else. It's not like contemplating nature, where we can see a mere fingerprint or footprint of God; mere evidence of Himself that He left behind. The Holy Eucharist truly is God and He truly is there in the Church. We are there to be intimate with God. The Holy Eucharist is the Carnal Intimacy between Christ and His Bride the Church. We are there to help each other to attain that union with God. We are there to escape this world and go to Heaven. God wants to love mankind, but most people in the world run away from Him into the empty pleasures of the world. That is the problem we exist to solve: to bring people out of the world and into the Divine Love for which they were created by God.