In this sermon, the speaker addresses the issue of Christians promoting a Roman Catholic movie as a witnessing opportunity. He warns against the movie's intent to elevate Mary to the level of the fourth person of the Godhead. The speaker also highlights the danger of false teachings, such as modalism and the combination of faith and works for justification, which can damn the soul. He emphasizes the importance of keeping a close watch on oneself and one's teaching to avoid falling into error and blasphemy against God.