Renunciation is not a thing that can be learned or taught. It comes by itself as the soul develops; when the soul begins to see the true value of things. All that is valuable to others, a seer soul begins to see otherwise. This shows that all things that we see as precious or not precious, their value is according to the way we look at them. For one person, the renunciation of a penny is too much; for another that of all he has is nothing. It depends on how we look at things. All things one renounces in life, one rises above. Man is a slave of the thing which he has not renounced; of things that he has renounced he becomes king. This whole world can become a kingdom in his hand if a person has renounced it. But renunciation depends upon the evolution of the soul. One who has not evolved spiritually cannot well renounce. For the grownup persons, little toys – so valuable to children, are nothing. It is easy for them to renounce this. So it is for those who develop spiritually – all things are easy to

The Messenger and Sign of God, Jesus Christ, upon him be God’s showering of blessings, said: “Do not take this world as a Lord – for it will take you as slaves. Entrust your treasures with One who will never lose them; for the possessor of treasure of this world fears the destruction of his treasure, but the possessor of the treasure of Allah does not fear the destruction of his treasure.”

Pearls of Muhammadan Wisdom
on Renunciation of the Worldly (Tark-e-Dunya)

Prophet Muhammad, peace be upon him, said: “This lower world (i.e. its pleasures and duration) in comparison with the Life in the Hereafter is (similar to the amount of water) one gets when he dips his finger in the Sea. Let him then see what it returns with”. – Al-Mustaurad bin Shaddad reported the above Hadith from collection of Imam Muslim

The Prophet said: “Be in this world like a stranger or wayfarer.” – Narratted by Abdullah bin Umar from collection of Imam Bukhari

One day the Messenger of Allah slept on a straw mat. When he stood up (we noticed) the straw mat left marks on the body of the Prophet (due to roughness of the straw mat). Ibn Mas’ood said, ‘Oh Messenger of Allah! had you ordered us we should have spread (a comfortable bed) for you. (Upon that) the Beloved one of Allah said, ’I do not have any love for the (comforts of the) world. My relationship with the lower world is nothing but like a traveler who (while traveling) seeks shadow under a tree and rest there and thereafter leaves.’ – Mishkaat, narrated by Abdullah ibn Mas’ood

The Prophet said: “I am not afraid that you will worship others besides One God, but I am afraid that the worldly life will tempt you and cause to compete with each other for it". – Narrated by Hazrat Uqba bin Amir from collection of Imam Bukhari

Allah’s Apostle said, “If Adam’s son had a valley full of gold, he would like to have two more valleys, for nothing fills his mouth except dust. And Allah forgives him who repents to Him.” – Narrated Anas bin Malik