I believe he interacts with us in the following ways (by no means exhaustive):
1. Personally, by direct revelation (that tugging in everyone’s heart that they are missing something)
2. By miracles
3. By the Bible (I have met people who were saved by those Gideon Bibles placed in hotels)
4. By evangelism of Christians
5. By attendance in church
There are a LARGE variety of ways Christ interacts with us; the church is but one. My biggest issue is with the author’s claim that the church is the only way. That is simply not scriptural.