To build a community whether Christian or not one must be part of that community.
How to build a Christian community is seen throughout the bible in the repeated mentioning of people gathering to worship, to take part in festivals feasts etc.
We see J esus as was his custom of attending the synagogue.
We have Paul command in Hebrews 10; . 24 And let us consider how we may spur one another on toward love and good deeds, 25 not giving up meeting together, as some are in the habit of doing, but encouraging one another—and all the more as you see the Day approaching.
Note we are to take part, not for what we gain, but for how we can contribute.