One of the more intolerable implications of Calvinism is that if it is true, God actually asks us to be more loving than He is. Calvinism, particularly from the perspective of Limited Atonement, would suggest that God does not, in fact, love the vessels of wrath. God's love is a thing that you either have, at which point He will regenerate your totally depraved heart and you will be unable to resist the call to salvation, or you don't, at which point God will simply never call you, may even harden your heart against Him, and you will remain unregenerate until you are eventually cast into Hell.
The problem with this is that it isn't the attitude He commands us to take. In fact, with us, He flat out condemns it. In the Sermon on the Mount, Jesus tells us "Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. For if ye love them which love you, what reward have ye? do not even the publicans the same? And if ye salute your brethren only, what do ye more than others? do not even the publicans so? Be ye therefore perfect, even as your Father which is in heaven is perfect." (Matthew 5:43-48).
As you can see, Jesus gives no exceptions. All human beings are to be the objects of our love, even if they are our enemies? Why? So we may be like our Father. He even gives examples; the Father makes the sun rise on the evil and the good, and sends rain on the just and the unjust. This really leaves no room for interpretation. Not only does it tell us that God loves His enemies, but also shows us how. Furthermore, He tells us that we must do likewise, loving not only the brethren (after all, sinners love their own), but even our enemies. Therefore, there are two possibilities. Either there is a limit to this command, or God expects us to love more people than Calvinism asserts He does.
There are several blocks to the former interpretation. Aside from the fact no limit is cited, multiple attempts to widen the scope are made. We are told to love our enemies, bless those who curse us, pray for those who persecute us. He even points out that even the publicans (perceived, at that time, to be the worst of sinners) salute only their brethren. So are we supposed to salute only the brethren? Or is it more likely Jesus' words here are a blanket that covers the entire human race?
Yet, if it covers the whole human race, then God's love must also encompass the whole human race. The first reason is that this passage tells us we do all this in order to be like God (actually going as far as to say "That ye may be the children of your Father which is in heaven" and "Be ye therefore perfect, even as your Father which is in heaven is perfect."). If we're doing this to be children of our Father, being perfect as He is, then He must be perfect in the sense described in this sermon. God must love His enemies. God must bless those who curse Him. God, while He hung on that cross, prayed "Father, forgive them; for they know not what they do." (Luke 23:34). If you can find a man for whom the sun will not shine, nor will the rain fall, then you have found a man who is no longer loved by God, but until then, the Sermon on the Mount makes no sense unless God loves all humanity, and expects us to do likewise.
And how could it? If God is the supreme being He is described as in scripture, how could He command us to exceed Him in anything? God cannot lie (Titus 1:2), so could He expect us to exceed Him in honesty? God cannot be tempted (James 1:13), so could He expect us to exceed Him in Holiness? God is love (1 John 4:8), therefore it is utterly insane to suggest God would ask us to exceed Him in love!
As non-divine creations, we can exceed God only in weakness. In love, we have no hope to even compare. We will more easily create a universe in 5 days than exceed God in love. Therefore, Calvinism simply cannot be true. There are people whom God, in His sovereignty, will allow to be condemned, but no one is beyond His love. When Jesus says God so loved the world, He meant it. Therefore, let Him mean it, and let us believe it, and if you cannot understand how a God who loves someone will allow them to be condemned, then acknowledge that the Holy Spirit exceeds you in knowledge and wisdom.