Now i am going to take the human side, and i think I hear somebody say ,-"though I liked the first part, I know I shall not like the second." Dear hearer, what right have you to cavil at aught that is true? somebody on the other hand may say, " "I do not believe on the first part, pherhaps I may in the second." My dear friend, I wish you would give up that notion of picking and choosing parts of Gods word that are agreeable to your taste; but rather take the whole from the beginning to the end of it, so you shall find pleasure and profit all the way though. Truly brethren, it is shocking to think of the theoretical difficulties that people make for themselves by a kind of smart criticism that seem clever, but lacks common sense.
in this verse
Joh 6:27 Labor not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath God the Father sealed.
the fact is, you get two paradoxes in one sentence. You are told not to labor for the meat which no man can procure without labor, and you are told to labor for that bread which no man can procure by labor because it is a free gift.
Howbeit, the thing needs no explanation. It is clear as daylight to every discerning heart. Here then is the human side of salvation:
Joh 6:40 And this is the will of him that sent me, that every one which seeth the Son, and believeth on him, may have everlasting life: and I will raise him up at the last day.
excerpt from a sermon called The Fathers will by C.H Spurgeon