Don't be from the people who do NOT understand the message of the Qur’aan:

بسم الله والحمد لله والصلاة والسلام على رسول الله ، وبعد

Shaikh al-Fawzaan حفظه الله in his Sharh (explanation) of Usool al-Sittah mentioned the following statement of Ibn al-Qayyim رحمه الله:

❝ The Qur’aan, the whole of it is about Tawheed, because:

1. It either commands to worship Allaah alone and to abandon Shirk.

2. Or it informs us about the reward of the people of Tawheed and the punishment of the people of Shirk.

3. Or it informs us about the Halaal and Haraam in Islaam - and this is from the rights of Tawheed.

4. Or it informs us about the stories of the Prophets and their nations and what took place between them of the disobedience and negligence.❞

Then Shaikh al-Fawzaan حفظه الله says:

❝ The whole of the Qur’aan is about Tawheed, from its beginning till its end. Yet there are people who recite this Qur’aan but commit Major Shirk. They say (with their tongues): لا إلهَ إلاّ الله (that none has the right to be worshiped except Allaah), but do not act on it (with their hearts and their limbs). They are in one valley while the Qur’aan and لا إلهَ إلاّ الله are in another valley. Rather, this is only a statement which they utter with their tongues (without understanding what it means or what it implies).

If you ask them: “What is the meaning of لا إلهَ إلاّ اللّهُ?”

They'll say: “I don't know. I did not learn about it.”

We say to him: So if you say لا إلهَ إلاّ اللّهُ and you do not know what it means, does this (characteristic) befit a Muslim?!

Do you say a statement which you do not understand and it does not bothers you?! Or do you say: I heard the people saying something, so I also said the same?! Like how the hypocrites will respond to the questions in the graves: ❝I do not know, but I heard the people saying something and so I said (the same).❞ [Saheeh al-Bukhaaree (86, 184, 922, 1053, 1338, 1374, 7287) and Saheeh Muslim (1977)]

Allaah تعالى says:

وَمَثَلُ الَّذِينَ كَفَرُوا كَمَثَلِ الَّذِي يَنْعِقُ بِمَا لَا يَسْمَعُ إِلَّا دُعَاءً وَنِدَاءً ۚ صُمٌّ بُكْمٌ عُمْيٌ فَهُمْ لَا يَعْقِلُونَ

{And the example of those who disbelieve, is as that of him who shouts to the (flock of sheep) that hears nothing but calls and cries. (They are) deaf, dumb and blind. So they do not understand.} [Surah al-Baqarah (2): 171]

Allaah تعالى likened them to the cattle which hears the sound of the shepherd and reacts to this sound but does not understand it.❞

[Sharh Usool al-Sittah (1/16-17)]