Stay away from five kinds of people:
1. A liar, as he will also betray you
2. A witless person, as he will try to benefit you, but will always cause you harm
3. A miser, for he will cause you intense loss in order to gain even the slightest benefit
4. A coward who will leave you in distress during a difficult situation
5. A man who is involved in illicit dealings, for he will sell you for one morsel and will still be hopeful of even less than that.
—  Imam Jaffar Sadiq
Prayer is that which enables the soul to realize its divinity. Through prayer human beings worship absolute truth, and seek an eternal reward. Prayer is the foundation-stone of religion; and religion is the means by which the soul is purified of all that pollutes it. Prayer is the worship of the first cause of all things, the supreme ruler of all the world, the source of all strength. Prayer is the adoration of the one whose being is necessary.
—  Ibn Sina, “Kitab al-Najat” 
The sun that rises sets; the flowers that blossom wither.
High buildings crumble, and all those who are born finally die.
O self! You are like a wasp going from one flower to another
You are full of greed and you are tempted by the worldly pleasures
Know that this world is a four day dream
And you will finally return to dust
—  Sayyed Muhammadshah in his Ginan “Ugamiya Sohi Din”
Lord, the night is gone. The dawn has lighted the sky. How I long to know if You accepted or rejected my prayers. Comfort me, Lord, for only you can comfort this state of mine. You gave me life and nurtured me; Yours is all the praise. If You would ever drive me away from Your door, I would never abandon it for the sake of Your love, which I carry in my heart.

-Rabi'a, “Rabi'a the Mystic" 

From "The Bounty of Allah,”