Modern Christianity is known, among other things, for teaching the idea of God's unconditional love. It is often spoken of in terms of evangelism, when believers express their concern for the "afterlife" of unbelievers. "God loves you unconditionally," they tell their unbelieving audience, "and He wants you to be with Him in heaven." I cringe every time I hear something like this said, not because I doubt the motivation behind the evangelistic sentiment, but because the unbeliever has such a perfect opportunity to ask a question of the believer that would probably end the conversation on the spot. Although I have never heard an unbeliever ask this question, it is important that we think about it so that we may be "always ready with an answer" (1 Peter 3:15).
What is the question? Simply this: "If God loves me unconditionally, why does it matter how I live my life?" Or it could also be phrased this way: "If God truly loves me unconditionally, why should it matter whether or not I 'become a Christian?'" Be careful to not miss how powerful and deadly this question really is. It is not just a clever twist of wording, meant to sidetrack the evangelistic efforts of well-meaning proselytizers. Far from it. This question is the stake in the heart of the modern evangelical notion of God's "unconditional love." In fact, I challenge you to search for the phrase "unconditional love" in the Bible or find the concept that God unconditionally loves every person on earth being taught anywhere in Scripture. In fact, R.J. Rushdoony makes the bold claim that "unconditional love is contrary to the Bible."
Unconditional love is a more revolutionary concept than any other doctrine of revolution. Unconditional love means the end of discrimination between good and evil, right and wrong, better and worse, friend and enemy, and all things else. Whenever anyone asks you to love unconditionally, they are asking you to surrender unconditionally to the enemy. 
Strong words, but necessary ones because modern Christianity finds itself exactly where Rushdoony claimed they would be: in an unconditional surrender to the enemy. Any situation that does not have "conditions" can play to the advantage of either side. Imagine entering a marriage with "no conditions." There would never be grounds for divorce (even in the biblical "condition" of adultery), because no terms were ever agreed to. We tend to think of unconditional love in a positive sense, but there is just as much an equal and opposite negative side. Rushdoony continues:
We are told to love our enemies, that is, those who offend us personally on non-religious and non-moral issues. When the cause of division is petty and personal, we must rise above it with an attitude of law and justice; we must continue to extend to all such persons the full protection of the law from injustice, malice, and false witness. But the enemies of God's justice and God's law, of fundamental law and order, must not be loved. To love them is to condone their evil. The accusation of the psalmist is to the point: "When you see a thief, you delight to associate with him, and you take part with adulterers" (Psalm 50:18, Berkeley Version). What we condone morally, we also approve of or delight in. St. John forbad hospitality to those who trying to subvert the faith: "If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed: For he that biddeth him God speed is partaker of his evil deeds" (II John 10,11). 
Notice that Rushdoony says that we are to love our enemies unconditionally, but never God's enemies. This is precisely what is wrong with saying that God's love is unconditional. We are applying a command that has been given to us by God back onto God Himself. While it is true that God loves his friends unconditionally, that love can exist only because Jesus Christ has already fulfilled the conditions of the friendship on the cross. The same Jesus who said "no longer do I call you slaves..but I have called you friends," also said that His friends do what He commands and "if you love Me, you will keep My commandments" (John 15: 14-15; 14:15). God's friendship/love is conditioned upon obeying Him and doing what He commands. If we show love for Jesus by keeping His commandments, then we also show hate for Him by not keeping them.
Those who preach unconditional love are simply trying to disarm godly people in order that evil may triumph. The same is true of the idea of unconditional forgiveness. Forgiveness in the Bible is always conditional upon true repentance. Unconditional forgiveness is simply the total, unconditional toleration of and acceptance of evil. It demands that we accept the criminal, the pervert, the degenerate, the subversive as they are. But to do so means that we must change. We must surrender our laws, faith, religious standards, and all godly order. The demands for unconditional love and unconditional forgiveness are demands for total change on our part, total revolution in society. They are in reality demands that we commit suicide in order that evil may live. 
By now you should begin to understand why I said that the unbeliever's question above is a deadly pill to modern evangelism. The very fact that we are telling the unbeliever to come to Jesus so that he might be saved from eternal punishment and separation from the holy God implies a condition. If God truly loved everyone unconditionally, there would be no need to evangelize. In fact, there would be no need for the church at all. If God was truly an "unconditional" God, then it wouldn't much matter if we gave Him praise or not, it wouldn't much matter if we read and taught His word or not, it wouldn't much matter if we lied, cheated, and stole our way to fame and fortune or worked diligently and honestly. In fact, the entire Bible would be a waste of time and effort if God did not expect us to learn something from it and respond to it in obedience and faithfulness. God's holiness is completely opposed to sin and disobedience. God's love is conditioned upon repentance and obedience, therefore it can never be offered as "unconditional."
 Rousas J. Rushdoony, Roots of Reconstruction (Vallecito, CA: Ross House Books, 1991), 625. Emphasis mine.
 Ibid, 626.
Recommended further reading:
Vincent Alsop: Practical Godliness
Herman Bavinck: Our Reasonable Faith
Arnold Frank: The Fear of God - A Forgotten Doctrine
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