As I was reading this, an idea began to form in my mind. The question was, what is the difference between CALLED and CHOSEN? What I found is mind-boggling. The Greek word for called is kletos. The emphasis of this word is that God is looking for someone. He has lost someone and is out in the night pleading and calling for them. The thought is that they are not returning an answer to him, yet he continues to call. My next question was who does this sound like in the Bible? Yes, I believe he is referring to the people of Israel. In fact, there are many references in the old testament of God calling to the Jewish people repeatedly and having them reject him.
The Greek word for chosen is eklektos (which is similar to the Greek word for church -ekklesia). I'm not familiar with the Greek language, so I can't say if this is significant or not. However, I do know that eklektos carries the connotation of "the highest calling" or "chosen by God to obtain salvation". This word indicates a positive response in the one who is called.
Now, back to the passage in Matthew 20. What is the context?
1For the kingdom of heaven is like unto a man that is an householder, which went out early in the morning to hire labourers into his vineyard.
2And when he had agreed with the labourers for a penny a day, he sent them into his vineyard.
3And he went out about the third hour, and saw others standing idle in the marketplace,
4And said unto them; Go ye also into the vineyard, and whatsoever is right I will give you. And they went their way.
5Again he went out about the sixth and ninth hour, and did likewise.
6And about the eleventh hour he went out, and found others standing idle, and saith unto them, Why stand ye here all the day idle?
7They say unto him, Because no man hath hired us. He saith unto them, Go ye also into the vineyard; and whatsoever is right, that shall ye receive.
8So when even was come, the lord of the vineyard saith unto his steward, Call the labourers, and give them their hire, beginning from the last unto the first.
9And when they came that were hired about the eleventh hour, they received every man a penny.
10But when the first came, they supposed that they should have received more; and they likewise received every man a penny.
11And when they had received it, they murmured against the goodman of the house,
12Saying, These last have wrought but one hour, and thou hast made them equal unto us, which have borne the burden and heat of the day.
13But he answered one of them, and said, Friend, I do thee no wrong: didst not thou agree with me for a penny?
14Take that thine is, and go thy way: I will give unto this last, even as unto thee.
15Is it not lawful for me to do what I will with mine own? Is thine eye evil, because I am good?
16So the last shall be first, and the first last: for many be called, but few chosen.
After reading this, it seems clear to me that he is talking about the fact that God has called and called to the Israelites, but they refused him. He then "hired" us, the Gentiles, and gave us the same wage/reward. This being true, it has nothing to do with following a formula. Rather, it has to do with God calling and us responding to his free gift of salvation. If you have not truly given your heart and life to Jesus Christ, I urge you today to surrender to him and accept the free gift that he lavished on us through Jesus.