Going to Mass is not just an obligation. I go because I am going to meet God in person, not only meeting him but also becoming one with him. Then God already dwells within me, so I go to receive him again in the Holy Eucharist to seal this intimate relationship one more time. I do not see any contradiction here because God is present everywhere, both within and without me. The Lord cleanses and heals me again, transforming me some more. At Mass, it's as if I were present at the Last Supper. At Mass, I get to celebrate again the Passion and Resurrection of the Lord. I won't want to miss Mass for all the world.