How do we know that the gospel is effective in changing lives?

The parable of the mustard seed illustrates the transformative power of the gospel. Although it may start small in an individual's heart, it has the potential to grow significantly, resulting in a person who becomes useful and impactful within God's kingdom. This hidden growth demonstrates that the gospel is not measured by immediate results but by its enduring impact on the lives of believers. As people embrace the gospel, they can find their identity and purpose in Christ, which leads to significant changes in their behavior and interactions with others.