Interesting Tidbit from the Cath Convert Billboard
Q: Surely, as Catholics, we have access to much more grace than the average Israelite had under the Old Covenant, so why aren't we much better morally?
A: One guess would be that we live in an age that is much more conducive to sin. Think about it, it's just as easy to type "www.redhotporn.com" as to type "www.catholic-convert.com." The internet gives easy access to all kinds of sin. Indeed, seemingly everything about our popular culture encourages materialism and sin. The very idea of sin is down-played and laughed at. Those who try to practice self-denial are looked on as bizarre and fanatical.
Our modern technology might also play a part. The more climate-controlled and comfortable our lives become, the less we feel the need for God. I believe one of the saints said that weather was the best penance because it comes to us directly from the hand of God. But we live in an age where it's possible never to see the weather if we so choose. We are insulated and isolated from life itself to a much greater degree than an Israelite in a tent who lives or dies depending upon when God sends rain.
I would also guess - though I don't know - that where grace abounds, demonic attack and temptation abounds as well. When God steps up His activity, I suspect that Satan steps up his, too.
Finally, I don't think our free will is much different than that of the ancient Israelites. Indeed, the human condition never really changes, which is why the Bible is as relevant to us today as it was when it was written.