I feel you are missing the point.
Christianity does not support slavery. It says absolutely nothing about slavery per say. It does support slaves and it does support slave masters. But the institution of slavery is irrelevant to the message of Christianity.
Hence the problem for atheists, but not for Christians.
Christians go to the New Testament and see no directive to engage in slavery so they don't
Atheists to the the New Testament and see no directive to prevent slavery, so the assume that Christians will automatically engage in it, not because Christians say they will (they deny it) but because atheists want to make it a point of contention to shore up their own views.
This is your bias at work. Not the Christians, who already start with a message of love and see no cause to do something unloving.
There's quite a few mistakes in there. Actual mistakes, which I am sure you will be glad to see corrected.
Let's see. In no particular order...
There is no "problem for atheists." Whether the Bible supports slavery, opposes it or is indifferent to it, the outcome for atheists is the same. Generally, they lack belief in God because they see no reason to believe in such an entity. The details of the story about this god that Christians speak of are only relevant to people who believe that He exists.
You say that Christianity does not support slavery. You seem to be conveniently forgetting the entirety of the Old Testament, in which God makes His feelings on slavery quite clear (as cvanwey, Clizby and I have demonstrated more than fully). It's worth noting that Christians believe Jesus to be, in some way, a part of God (let's not get into the whole amusing mess of the Trinity) and so when God was commanding slavery and giving instructions on how to carry it out, Jesus was speaking the commands Himself.
You furthermore claim that the New Testament does not endorse slavery. This is false. The New Testament writers clearly stated that slavery glorified God and was pleasing to Him, on numerous occasions. Since the system of slavery was already fully established, both by the Old Testament and the Roman Empire, naturally they felt no need to re-invent the wheel and so contented themselves with explaining that their new religion did not contradict slavery - indeed, quite the opposite, slavery as an institution fitted in well with it.
And, as we've already covered exhaustively, that is exactly what they did. I trust you recall the instances we showed you in which the New Testament Writers, extolled the virtues of slavery. They did not, as you claim, merely "support slaves and masters". They said that it was pleasing to God when slaves obeyed their masters, and displeasing to Him when they disobeyed. In this, they showed the institution of slavery was pleasing to God and in line with His view of the world (as any Christian who has read the Old Testament will already know).
You have a lot to say about how Christians see the world and how Christians love others, but this is false. This is how
you see the world, and the Christians around you, and you assume that all Christians throughout history, right up to Paul and Jesus themselves, must also have seen it (at least, if they were thinking correctly). You look at the Old and New Testaments with the eyes of a modern, western citizen - ironically, exactly what you accused me of doing - and you assume that what you mean by "good" and "loving" is what the writers of the Bible did.
But if you look at what they actually said, it's clear that they saw slavery as ordained by God and pleasing to Him; and Christians throughout history have agreed with this. If you want to disagree with them, then feel free to do so, but don't try to convince us that this is what the Bible says. Because we can read it for ourselves. Yes, slavery is wrong. Yes, the Bible said it was right. Yes, the Bible was wrong to do so.
