"Now you dwellers in Jerusalem and men of Judah,
judge between me and my vineyard.
What more could have been done for my vineyard than I have done for it?
When I looked for good grapes, why did it yield only bad?
Now I will tell you what I am going to do to my vineyard:
I will take away its hedge, and it will be destroyed;
I will break down its wall, and it will be trampled.
I will make it a wasteland, neither pruned nor cultivated,
and briers and thorns will grow there.
I will command the clouds not to rain on it."
The vineyard of the LORD Almighty is the house
and the men of Judah are the garden of his delight.
And he looked for justice, but saw bloodshed;
for righteousness, but heard cries of distress.
Then he told this parable: "A man had a fig tree, planted in his vineyard, and he went to look for fruit on it, but did not find any. So he said to the man who took care of the vineyard, ‘For three years now I’ve been coming to look for fruit on this fig tree and haven’t found any. Cut it down! Why should it use up the soil?’ "‘Sir,’ the man replied, ‘leave it alone for one more year, and I’ll dig around it and fertilize it. If it bears fruit next year, fine! If not, then cut it down.’" Luke 13:6-9The Lord is patient, but as he plants the Word and fertilizes it in our lives he expects to see fruitfulness. If not then he brings chastening or a more permenant form of judgment. Notice also John 15:1,2,6 "I am the true vine, and my Father is the gardener. He cuts off every branch in me that bears no fruit, while every branch that does bear fruit he prunes so that it will be even more fruitful." ... "If anyone does not remain in me, he is like a branch that is thrown away and withers; such branches are picked up, thrown into the fire and burned."
It is interesting that God's efforts to plant and fertilize do not necessarily result in the fruitfulness. This implies that cooperation on our parts is necessary to bear fruit. Thus we need to insure that what God is doing in our lives results in fruitfulness. But let us make a clear distinction here between one being unfruitful and their efforts to edify others being unfruitful. Is God unfruitful? No, in this case it's his vineyard which is unfruitful. His efforts though good had been in vain.
What about a Christian involved in minstering the gospel but whose efforts also seem in vain? Many efforts, for example, among the Islamic community have produces few conversions. And there are many other such environments in which Christian's efforts have had little impact. While we all have our particular vineyards, our ministries, our pools of influence, we learn from this passage to be careful to not necessarily blame the Christian if their efforts haven't brought forth the desired effect. At times even God can't make his own vineyard produce fruit.
If we judge others based upon whether their relationships turned out good, then we'd have to say that God failed as a father (Isaiah 1:2), God failed as a husband (Jeremiah 3:8), and God failed as a farmer (Isaiah 5:2). Thus those Christians who have failed in similar areas can rejoice and take comfort in being able to identify with God's own experiences.
Another thing we learn from this passage is that God's patience in endeavoring to make his vineyard produce fruit is limited. This attitude is also reflected in Jesus' parable of the unfruitful fig tree quoted above. So also as we minister in people's lives. If we continually meet with resistance there needs to be a time when we shake the dust off our feet and move on perhaps to return some time later. In some case we might sow for a few years as Jesus parable above mentions. In other cases if the ground is completely unsuitable we need to move on until the Lord breaks up the soil. "If anyone will not welcome you or listen to your words, shake the dust off your feet when you leave that home or town. I tell you the truth, it will be more bearable for Sodom and Gomorrah on the day of judgment than for that town." Matt 10:14,15
While these concepts apply to evangelism, they also apply to discipleship as well. Afterall, the God's vineyard was not symbolic of outsiders, but of his people, as nominal in faith as they may be. So also in discipling Christians or involvment in church ministry is also working in a vineyard. You will encounter resistance. But persevere in it, just as God doesn't give up right away at the first sign of trouble. However if resistance to edification persists over a long time then it may be time to move on and pray for such Christians to experience God's discipline.