While reading about him it was mentioned that he, himself, wrote some books. I decided to check one out at the library titled "Life Together: The Classic Exploration of Faith in Community".
According to the back cover this work is Bonhoeffer's "account of a unique fellowship in an underground seminary during the Nazi years in Germany".
As I began reading it, even the first pages gripped me.
(underlining for emphasis mine)
"It is not simply to be taken for granted that the Christian has the privilege of living among other Christians...
It is by the grace of God that a congregation is permitted to gather visibly in this world to share God's Word and sacrament. Not all Christians receive this blessing. The imprisoned, the sick, the scattered lonely, the proclaimers of the Gospel in heathen lands stand alone. They know that visible fellowship is a blessing...
It is true, of course, that what is an unspeakable gift of God for the lonely individual is easily disregarded and trodden under foot by those who have the gift every day. It is easily forgotten that the fellowship of Christian brethren is a gift of grace, a gift of the Kingdom of God that any day may be taken from us, that the time that still separates us from utter loneliness may be brief indeed.
Therefore, let him who until now has had the privilege of living a common Christian life with other Christians praise God's grace from the bottom of his heart. Let him thank God on his knees and declare: It is grace, nothing but grace, that we are allowed to live in community with Christian brethren..." ~~Dietrich Bonhoeffer