What is the response to the claim that learning tawhid (the oneness of Allah) is not necessary in lands whose environment is tawhid?

Question:
What is the response to those who say that the people in these lands are in an environment of tawhid and upon sound fitrah (the innate natural disposition), so why are they occupied with learning tawhid?

Answer:
Subhan Allah, meaning are we safe from shirk (associating partners with Allah) and from what? Who is safe regarding himself? Ibrahim (peace be upon him) said: He feared for himself, even though he was the one who broke the idols and was thrown into the fire because of that, and yet he feared for himself, and the reason is .
Fitnah (trial, discord or temptation), may Allah protect us, and no one is safe from shirk. It is not enough to say, "I am a monotheist and I do not associate partners with Allah." No, if you do not know shirk, you will fall into it. You must learn what shirk is and the types of shirk so that you avoid them, and do not declare yourself righteous. Do not say, "I am protected and I am in the shadow of One greater than you." They strayed and deviated.
Fear the fitnah, my brother. The fitnah is great now, as you know. The trials are great and varied now, and they reach people while they are on their beds in their houses, with their doors closed, entering upon them through the evil media that you know. So the trials are great, and no one is safe for himself. Do not declare yourself righteous, and do not feel safe for yourself. Yes.