I'm a person who is very—very—longsuffering, or patient. Sometimes, apparently, I'm even more patient than God is. This is a personality characteristic that I've received from the Holy Spirit—a fruit of the Spirit, which develops in the life of the Christian, over time. As St. Paul puts it, "But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such there is no law." (Galatians 5:22-23).
Christ said: "For no good tree bears bad fruit, nor again does a bad tree bear good fruit; for each tree is known by its own fruit. For figs are not gathered from thorns, nor are grapes picked from a bramble bush. The good person out of the good treasure of their heart produces good, and the evil person out of their evil treasure produces evil; for out of the abundance of the heart their mouth speaks. (Luke 43-45).
People don't like to think about this, but God does give up on some people: he gives them over to a reprobate mind (see Romans 1:18-32). When God patiently, mercifully, and abundantly pours his love and his mercy upon these people, and yet they choose to reject him and his wisdom—preferring their own self-centeredness to God and their own foolishness to his wisdom—he is left with little choice but to cut them loose; forever.
This is a very frightening thought.
Interestingly enough, immediately before the passage I just quoted above—concerning the good tree that can only bear good fruit and the bad tree that can only bear bad fruit—Christ condemns hypocrites for their arrogant, self-righteousness, and foolish behavior: "Or how can you say to your brother, 'Brother, let me take out the speck that is in your eye,' when you yourself do not see the log that is in your own eye? You hypocrite, first take the log out of your own eye, and then you will see clearly to take out the speck that is in your brother's eye." (Luke 42-43).
The hypocrite is a fool; a fool who wears a mask of Christianity but their actions—their bad fruit—betray who, in fact, they really are: bad trees that are incapable of bringing forth good fruit.
Again—very interestingly—in Matthew's gospel, immediately after the passage which I just quoted above, which is from Luke's gospel, wherein Christ condemns the hypocrite for their foolish attempt to remove the speck from their brother's eye while there is a beam in their own eye, Jesus says to his followers: "Do not give dogs what is holy; and do not throw your pearls before swine, lest they trample them under foot and turn to attack you." (Matthew 7:6).
What is Christ talking about here? Who is he talking about? Aren't we supposed to present the gospel (i.e., the pearl) to everyone?
As John Stott explains it, ". . . the dogs and pigs with whom we are forbidden to share the gospel are not just unbelievers. They must rather be those who have had ample opportunity to hear and receive the good news, but have decisively—even defiantly—rejected it" (Christian Counter-Culture: The Message of the Sermon on the Mount, (Downers Grove, IL: InterVarsity Press, 1973) p. 182)
Stott tells us that, "If people have had plenty of opportunity to hear the truth but do not respond to it, if they stubbornly turn their backs on Christ, if (in other words) they cast themselves in the role of "dogs" and "pigs", we are not to go on and on with them, for then we cheapen God's gospel by letting them trample it under foot." "Can anything be more depraved" Stott asks, "than to mistake God's precious pearl for a thing of no worth and actually to tread it into the mud?" Stott also acknowledges that, "At the same time, to give people up is a very serious step to take. I can think of only one or two occasions in my experience when I have felt this was right. This teaching of Jesus is for exceptional situations only; our normal Christian duty is to be patient and persevere with others, as God has patiently persevered with us" (ibid, p. 183).
As I said, at the beginning of this post, I am a very—very—longsuffering (or patient) person. Like Stott, when it comes to "giving people up", I can only think of two people in my experience when I've felt (I would say known) that this was the right thing to do. The first was a person I once worked with (for a year and a half) and the second was a woman I'd been living with (until a couple of months ago when we went our separate ways) for the past two years.
God uses people—Christians— to express his love, kindness, mercy, and grace. But when we have done all that we can do for someone (and then some),—again and again and over and over—and their only response is to turn upon us and attack us, we are to cut them loose; just as God has cut them loose.
We don't like to think of God's cutting someone loose, but he never does so without first giving these people—abundantly and beyond measure—all that he can of his love, his mercy, and his kindness. When these people spit in his face—and his people's faces—the Bible tells us that God will give these people over to a reprobate mind so that they might believe a lie and be damned (see 2 Thessalonians 2: 10-12).
These people are those who prefer lies to the truth, foolishness to wisdom, darkness to light, and hatred to love. They will lie to their friends, to their families, and even to themselves. But God knows the secret places of their hearts, because all things are naked and open to him (see Hebrews 4:13).
It truly is a fearful thing to fall into the hands of the living God after having spurned his love, his kindness, and his mercy. But God will not be mocked and these people will certainly reap what they've sown (see Galatians 6:7).
"For if we sin deliberately after receiving the knowledge of the truth, there no longer remains a sacrifice for sins, but a fearful prospect of judgment, and a fury of fire which will consume the adversaries. A man who has violated the law of Moses dies without mercy at the testimony of two or three witnesses. How much worse punishment do you think will be deserved by the man who has spurned the Son of God, and profaned the blood of the covenant by which he was sanctified, and outraged the Spirit of grace? For we know him who said, "Vengeance is mine, I will repay." And again, 'The Lord will judge his people.' It is a fearful thing to fall into the hands of the living God."