Karl Barth preached to the Basel prisoners at the end of his life until his health no longer allowed it. It was often said that many considered committing crimes so that they would be privileged to hear Barth preach. Thankfully, a collection of these prison sermons from 1954-1959 have been collected and published in the book Deliverance to the Captives. I've selected a quotation from two sermons in the book as sample.
The sermons are not weighed down by theological jargon, and the language is simple. The sermons are roughly 10-15 minutes long and are based on a single verse of scripture, or even a part of a verse. The sermons begin with a prayer and the sermon text, and the content is not weighed down by theological jargon or greek words, and the language is simple. Karl Barth knows his audience who is hearing the sermon. The sermons may contain references to personal in Barth's life or real life events known to the prisoners such as folk stories or recent events in the Basel surrounding region. The conclusion is with a prayer, which Barth says that these open and closing prayers should not be separated from the sermon text, and the concluded with saying the "Our Father..." prayer.
From "Saved by Grace", preached on 14 August 1955. The text was "By grace have you been saved" (Eph 2:5).
You probably all know the legend of the rider who crossed the frozen Lake of Constance by night without knowing it. When he reached the opposite shore and was told whence he came, he broke down, horrified. This is the human situation when the sky opens and the earth is bright, when we may hear: By grace you have been saved! In such a moment we are like that terrified rider. When we hear this word we involuntarily look back, do we not, asking ourselves: Where have I been? Over an abyss, in mortal danger! What did I do? The most foolish thing I ever attempted! What happened? I was doomed and miraculously escaped and now I am safe! You ask: 'Do we really live in such danger?' Yes, we live on the brink of death. But we have been saved. Look at our Saviour and at our salvation! Look at Jesus Christ on the cross, accused, sentenced and punished instead of us! Do you know for whose sake he is hanging there? For our sake--because of our sin--sharing our captivity--burdened with our suffering! He nails our life to the cross. This is how God had to deal with us. From this darkness he has saved us. He who is not shattered after hearing this news may not yet have grasped the word of God: By grace you have been saved!
Barth, Karl. Deliverance to the Captives. Trans. M. Wieser. New York: Harper & Row, 1961. 38. Print.
From "You Shall Be My People", preached on 7 October 1956. This sermon was delivered in Bruderholzkapelle, Basel. The text was "I will walk among you, and will be your God, and you shall be my people." (Lev 26:12).
God continues: 'I will stand by you, I will take sides with you, I will declare my unconditional solidarity with you, against all odds, against the whole world and all of mankind if need be, in particular against your own self!' Is it not true that man is his own worst enemy? Is not the most valuable partisan and helper one who, just because he is for us, dares to be mightily against us? God is this strong partisan and helper. We might also say: God in his divine determination and his divine perfection will say 'yes' to us. But God's 'yes' is a holy and wholesome 'yes', comprising always a 'no'. It is the 'no' to everything in us and about us which he must reject for his sake and our own. He treats us like a doctor who prescribes pills and medication we utterly dislike. I shall never forget how as a little boy I had to drink a glass of cod-liver oil every morning for many years. It tasted terrible, but it obviously did me some good. The doctor may even send us to the hospital, certainly not a very cheerful place. He may perform a minor or major operation, a most disagreeable undertaking indeed, yet how important for recovery! This is how God's 'yes' with the loathsome 'no' in it works. Be not anxious. God says 'yes' to us fully, unconditionally and unquestionably. He wills, he is able, to rescue us, to support us, to put us on our feet, to make us free and joyful. This is what 'I will be your God' means. In short, I will be what is beneficial to you, your good against all evil, your production against all disaster, your peace against all strife. In this way, walking among you, I will be your God!
Barth, Karl. Deliverance to the Captives. Trans. M. Wieser. New York: Harper & Row, 1961. 63-4. Print.