I don't remember where it was that I heard this, but recently I heard someone question the propriety of the phrase "go to church". Perhaps it was Jeff Vanderstelt at the Gospel Conference (Session 1 or 2), who I remember at the very least never using that phrase but substituting "gather with the church" or something similar. It could have been in Total Church. Maybe it was somewhere else. At any rate, "being the church" over against "going to church" is a popular topic, at least according to Google.
The concern about phrasing arises from understanding the meaning of "church". In the New Testament, "church" is always the redeemed community of Christ-followers. Sometimes it refers to the local church (Rom 16:5; 1 Cor 16:19), sometimes to the universal church (Eph 5:25; Mat 16:18), but in no case does it refer to anything like a building or an event that one could go to. I don't think that this teaching is controversial or peculiar to those who have been emphasizing the missional nature of church.
Although many of us who are Christians know this doctrine about the church, nonetheless our language more often than not refers to church as someplace to go or a meeting to attend. For example, Holly and I commonly refer to what we do Sunday morning as "going to church". Likewise we call our Sunday evening activity "going to Regen", and during the week, we "go to community group". Fundamentally, church, Regeneration, and community group are all communities of people, yet we refer to a meeting or gathering of it as if it were the thing itself.
While I don't want to get hung up on the phrasing per se, I do think that the way we say things both reflects and shapes the way we think about those things. When someone says "church", what is the first thing that comes to your mind? What do you visualize? When I hear that word, the first thing that comes to my mind is the Bear Valley Church building, perhaps an image something like this (but with more of Kendrick Lake in the background).
I don't know whether it is worth going to the effort to train myself to abandon the language of "going to church". But I do know that I need to cultivate an attitude of rightly seeing the church as the community of those who are redeemed in Christ and to live out my identity as part of that community all the time, not just at our gatherings. Maybe changing the way I talk about it will help.