1. When comes the Help of Allah, and Victory,
2. And thou dost see The People enter Allah's Religion in crowds,
3. Celebrate the Praises of thy Lord, and pray for his Forgiveness: For He is Oft-Returning.
This passage means to be humble, especially when teaching about Islam (and any religion, really). In the event that you see many turn toward a given religious path, it is not because of your effort, but because the teachings of that particular path spoke most strongly to their hearts. God has many forms and names. There are many paths to the Divine.