I Have Two Moms
I'm sure this is a provoking statement, but it's true. I've been giving this a lot of thought over the last month and I can see how it's true. I haven't really considered the church more than a gathering place where I went to learn about God.
I absolutely have brothers and sisters in church that can serve as the "arms and feet of Jesus", but that's not entirely what the church is. There is absolutely a relational sense to how the church is constituted, but I think it is broader than that. The church is an institution. The Reformed believe in three kingdoms (or domains) in life. The family, the church, and civil government. They are all instituted by God as institutions.
I think asking what is an "institution" is an appropriate question? Merriam-Webster offers the following: "a significant practice, relationship, or organization in a society or culture". The family, church, and civil government serve as foundational fundamental units God has established for us to organize our society and culture around. Meaning we group ourselves into like-minded groups where we serve the institutions goals. In a family, it's the rearing of children for the good of the society as a whole. In the church, for the worship of whatever god the group deems appropriate to worship and better themselves through the practice of a religion to that end. In civil government, along political lines to better the land we live in and serve others through employment and monetary development and growth.

While most Christians have no problem recognizing church as an institution they miss the forest for the trees...they see all the people and miss the "body" as a whole. Jesus spoke of the church as His bride, so it is a single unit...as well as individual parts. We can't ignore the bigger picture!
Theology used to be called the "queen of the sciences". That recognizes the nature of the church as "mother". I think we need to recover that and seek the nurture of our spiritual mother in times of struggle!