Pastor Tim's sermon focuses on the book of Revelation, emphasizing the importance of being aligned with Jesus in the end times. He highlights the prevalence of spiritual compromise then and now, warning against the dangers of compromising one's faith. The vision in Revelation 19 symbolizes Jesus as the victorious judge who will defeat the enemies of God. The sermon concludes by stressing the urgency of repentance and aligning oneself with Jesus, who will ultimately triumph over evil in the end times.