The First Major Sin: Associating partners with Allah.
The greatest of the major sins is associating partners with Allah the Exalted, and it is of two types.
One of them is to set up for Allah an equal and worship something else, such as a stone, tree, sun, moon, prophet, saint, star, angel, or anything else.
And this is the major shirk that Allah mentioned.
Allah the Exalted said: 'Indeed, Allah does not forgive associating partners with Him, but He forgives what is less than that for whom He wills.'
And He said: 'Indeed, shirk is a great injustice.'
And He said: 'Indeed, whoever associates partners with Allah, Allah has forbidden Paradise for him, and his abode is the Fire.'
And the verses concerning this are numerous.
So whoever associates partners with Allah and then dies as a polytheist, he is certainly among the companions of the Fire.
Just as whoever believes in Allah and dies as a believer is among the companions of Paradise, even if he is punished by the Fire.



