A summary of the concepts held by the Ahl al-Sunnah.
Hidden shirk and showing off (riya').
Allah the Exalted says:
“And most of them believe not in Allah except that they attribute partners (unto Him).” (12:106)
Just as this verse applies to the major shirk that expels one from the fold of Islam,
it also encompasses the hidden, minor shirk,
from which many people are rarely free,
as it creeps into their hearts without them even noticing.
It is more subtle to them than the crawling of an ant.
Among them are those who associate a worldly cause with the power of Allah,
or those who, while hoping in Allah, also attach their hopes to His servants,
or those who, while striving in the path of Allah, covet the attainment of worldly gain.
As the Exalted said to the Companions on the day of Uhud:
“Allah verily made good His promise unto you when ye routed them by His leave, until (the moment) when your courage failed you, and ye disagreed about the order and ye disobeyed, after He had shown you that for which ye long. Some of you desired the world, and some of you desired the Hereafter. Therefore He made you flee from them, that He might try you. Yet now He hath forgiven you. Allah is a Lord of Kindness to believers.” (3:152)
The most emphatic and dangerous form of this hidden, minor shirk
is showing off (riya').
This is as the Prophet, peace and blessings of Allah be upon him, said:
"The thing I fear most for you is minor shirk."
They asked, "O Messenger of Allah,
what is minor shirk?"
He replied:
"Showing off (riya')."
Allah will say on the day when servants are recompensed for their deeds:
"Go to those for whom you used to show off your deeds in the world,
and see if you find any reward with them."
It is sufficient to illustrate the gravity of showing off
that it nullifies one's deeds, as mentioned in the aforementioned hadith.
And as is also stated in the hadith qudsi:
"I am the most self-sufficient of partners, having no need for any association.
Whoever performs a deed in which he associates someone else with Me,
I leave him and his shirk."
The harms of seeking worldly gain through deeds intended for the Hereafter are not limited
to the nullification of the reward for those deeds on the Day of Resurrection;
rather, it also becomes a cause for the loss of worldly success at the level of the Ummah.
For if some believers were to make the world the primary driver of their actions,
failure and discord would occur among the believers, just as happened on the day of Uhud.
Allah the Exalted said:
“Allah verily made good His promise unto you when ye routed them by His leave, until (the moment) when your courage failed you, and ye disagreed about the order and ye disobeyed, after He had shown you that for which ye long. Some of you desired the world, and some of you desired the Hereafter. Therefore He made you flee from them, that He might try you. Yet now He hath forgiven you. Allah is a Lord of Kindness to believers.” (3:152)
“Allah verily made good His promise unto you when ye routed them by His leave, until (the moment) when your courage failed you, and ye disagreed about the order and ye disobeyed, after He had shown you that for which ye long. Some of you desired the world, and some of you desired the Hereafter. Therefore He made you flee from them, that He might try you. Yet now He hath forgiven you. Allah is a Lord of Kindness to believers.” (3:152)