The Quran, chapter 39 (Az-Zumar), verse 3:
Surely, the religion (i.e. the worship and the obedience) is for Allah only. And those who take Auliyaa' (protectors and helpers) besides Him (say):
"We worship them only that they may bring us near to Allah."
Verily, Allah will judge between them concerning that wherein they differ.
Truly, Allah guides not him who is a liar, and a disbeliever.
— translated by Muhammad Muhsin Khan
The Quran, chapter 31 (Luqman), verse 33:
O mankind! Be afraid of your Lord (by keeping your duty to Him and avoiding all evil),
and fear a Day when no father can avail aught for his son, nor a son avail aught for his father.
Verily, the Promise of Allah is true, let not then this (worldly) present life deceive you, nor let the chief deceiver (Satan) deceive you about Allah.
— translated by Muhammad Muhsin Khan