How do we know the concept of spiritual harvest is important?

In John 4, Jesus uses the metaphor of a harvest to teach His disciples about the urgency of spiritual work. He instructs them to lift their eyes and see that the fields are white for harvest, representing the readiness of souls to receive salvation. This indicates a profound truth within the mission of the church: there is a responsibility to proclaim the gospel and gather those whom God has called. The harvest signifies not just the physical act of gathering crops, but the eternal significance of rescuing souls from darkness into light. Believers are called to labor in this harvest, understanding that they are to participate in God's redemptive plan, pointing to the importance of evangelism and discipleship.