Jesus said to them after being asked to eat some food:
“My food is to do the will of him who sent me and to accomplish his work. Do you not say, ‘There are yet four months, then comes the harvest’? Look, I tell you, lift up your eyes, and see that the fields are white for harvest." John 4:34-35 (ESV)
I've read this passage multiple times; however I always associated it within the same context as Deuteronomy 8:3 where it reads that "man does not live by bread alone, but man lives by every word that comes from the mouth of the LORD." So when I read the passage from John I always associated Jesus saying that His food is not of this earth, but comes from God. However that's not at all what he is trying to show here. Jesus' food says nothing about receiving, but only giving. His food, what feeds him, is work; is labor; is to do, not to receive. I think that is very critical not to miss here. He came as an example of servitude. However crazy that may seem that the Lord, our God, came to serve, it nonetheless is what is repeated in Scripture over and over again. We are to follow His example that he set forth.
Yes we are saved by His grace through our faith in Christ, but faith without works is dead as James says. I think we all too often may attend church service thinking that we are being spiritually fed. However as a pastor once said, church is not to feed you, it's to make you hungry (Dave Wilson, Pastor/Chaplain). What should feed us, what should satisfy us to the deepest part of our soul, is to do His will, and accomplish His work.
Are you ready for the harvest, or do you plan to wait another 4 months?