What the Rav said:
Rabbi Natan said that all the sins will become merits.
Because sins are only to give a person a heart of flesh and humility.
That’s why they make a person fall all the time into sins.
A person has arrogance, he thinks he’s already a Tzadik, so they throw him down from the highest place to the lowest depths. He starts making all types of terrible blemishes, because he thinks he’s already a Tzadik and he’s already perfect. So, they throw him down, again and again.
Until, he strengthens himself and doesn’t fall into despair, and gets up and encourages himself – a Tzadik falls seven times and then gets up.
There’s a big discussion about free choice. How much is actually ‘me’ and how much is just ‘Hashem’ deciding everything for me. I don’t know the answer to this. From the little I’ve learned, I think it’s one of those questions that cannot be answered in this world.
However, here we have an indication from the Rav that suggests that Hashem causes a person to sin for his own good.
Why is it ‘good’ that a person sins?
I learned somewhere (I think from Likutei Moharan, but I’m not too good on remembering sources) that Rabbenu taught that the only thing which will remain of a person in the next world is his humility.
Hashem wants us to have something to take with us and is doing us the greatest kindness by throwing us down and, in some sense, causing us to sin.
Being brought down to earth is what gives us some humility (hopefully, if we get the message).