Man cannot, under any circumstances, live without religion.
Just as man is social by nature and cannot live alone and be isolated from society, he is also innately devout and cannot live properly without religion. Religiousness is a natural instinct in man.
The clearest proof of this is that man flees to Allah Almighty when facing difficulties and hard times. Allah says: }And when they embark on a ship, they invoke Allâh, making their Faith pure for Him only, but when He brings them safely to land, behold, they give a share of their worship to others{<small>(Al-’Ankabût: 65)</small>
Man has two powers: the power of knowledge, and that of will; and the more effort he exerts to achieve them, the closer he becomes to reaching the goal he desires. Such is the case with happiness. As for the first, i.e. the strength of knowledge; the highness of his degree of servitude to Allah, as well as the degree of his status, his happiness in this world, not to mention the Afterlife, all depend on the extent he knows Allah, His names and attributes, what he should and should not do, and his behavior and the personal code of ethics he adopts. This is also affected by whether he takes the path of those who are close to Allah and the lofty path of those who tread the route that leads to Allah, and if he possesses knowledge of the human soul with its diseases and impurities, and knows how to overcome them, its enemies and all that comes between it and its Lord. One needs to know how to lift the soul high and purify it with godly ethics in a manner that elevates it to the level of exalted souls, makes it attain a firmness of purpose and keeps it away from nonsensical materialistic issues and the filth of desires and suspicions. The more one does this the higher ones level of worship and ones place (with Allah) will be, even the level of his happiness in this life, and of course his final position in the Afterlife, will be higher.
Moreover, this power of knowledge is the benefactor and the provider of willpower, surrounding him with guidance, as well as making him steadfastness and righteousness. Allah says: }O you who believe! Answer Allâh (by obeying Him) and (His) Messenger when he (pbuh) calls you to that which will give you life.{<small>(Al-Anfâl:24)</small>
source: Why do we need religion in our life? – Path to Happiness