In this sermon, the speaker shares his experiences of preaching the word of God in various challenging environments. He talks about the exhaustion and difficulties he faced while delivering multiple sermons a day. Despite feeling inadequate and facing hostility, he relies on prayer and obedience to God's calling. The speaker emphasizes the importance of not manipulating God through fasting and highlights the power of God's strength in our weakness. He also describes a specific instance where he preached to Jewish university students who initially showed hatred and opposition, but he boldly proclaimed the kingdom of God and the collision between life and death.