Noun indeed.

But swearing when you hit your thumb with a hammer is hardly the same level of sin as committing genocide for fun and excitement.
Isn't the whole purpose of sin to learn from it and thereby being redeemed from it?
This reminds me of the "thorn in the flesh" Paul had (2 Corinthians 12:7). I've read where some people think his thorn was sickness and that God sometimes gives people sickness to make them a "better" Christian. My response to that is if that's true then a person shouldn't pray for their sickness to go away but to continue in order for them to be a "better" Christian. That is the goal, afterall.
My point is that you don't have to succumb to sin in order to learn about it. I'm not sure what lessons can be learned from sin itself. Although the consequences as a result of them might have some benefit, if that's what you mean. However, most sinners know right from wrong and yet many continue to sin anyways. The only thing they might learn is how to escape some of the consequences.
And isn't it be preferable to learn the lesson before actually comitting the sin?
See above.
Isn't that in fact what a major part of the lessons in the Bible are about?
The "major part of the lessons", imo, is about God's love and forgiveness. I suppose, in that sense, sin plays a role. But then, Jesus was sinless and yet he had to learn about God's love and forgiveness just like the rest of us. So, I'm not sure being a sinner is necessary to learn about God's will.
Also, the reason for our little detour from the thread subject was considering the push that "doubting Thomas" received. Should we just expect God to always give pushes, and not have to apply any standards to faith ourselves?
Everyone gets a "little push" from God. Most just don't realize it.
1 Kings 19:11-12
And he said, Go forth, and stand upon the mount before the LORD. And, behold, the LORD passed by, and a great and strong wind rent the mountains, and brake in pieces the rocks before the LORD;
but the LORD
was not in the wind: and after the wind an earthquake;
but the LORD
was not in the earthquake:
12And after the earthquake a fire;
but the LORD
was not in the fire: and after the fire
a still small voice.
That "whisper" is easy to miss or mistake for something else. I wonder, however, if God was to shout at us would it break our "ear-drums"?