Then the Head of Grain

This "ear" or "head" of grain is what is going to eventually be harvested as a life lived unto God. But it takes time to grow up into Christ. The Christian will grow with a growth that is from God. But they themselves will help promote this growth as they go about to live their life in obedience to God's word. They do this by faith in Christ, realizing that without His grace and strength and help, they can do nothing to cause their own growth. Therefore they strive to grow in obedience to God's word, and they think and praying of how they can grow up into Christ-likeness. That is the way that a Christian can bear fruit unto God. But the earth will yield crops of itself.