Islam gives spiritual peace.
The faith in God is a medicine for any spiritual ills; it helps regulate psychic urges which are themselves the mainspring of man's spiritual afflictions.
With faith, life has a beauty about it, because when one has the conviction that everything does not come to an end with this life it creates an inner peace and makes him pass through the entire course of life with steadiness, strength, and moderation.
Qualities like greed and avarice, which are one of the reasons for anxiety, are moderated as a result of faith in God. The hope of great rewards and the fear of severe punishments make man refrain from excessive greed and avoid unreasonable and uncontrolled passion for material things, glitter and ostentation. Thus, a desirable and serene equilibrium worthy of man's humanity is brought about within his soul.
Similarly, faith in the Day of Judgement and the hereafter removes the intolerable strain induced by the idea of absolute annihilation and extinction from the human spirit, for the person with such a faith is convinced that at the threshold of death the door to another world will open in front of him and he will enter an eternal life and its everlasting bounties that cannot be compared with the joys of this world. This faith results in eliminating another agent of mental anxiety which is the anguish of absolute nonexistence.
Islamic Faith not only cures anguish and anxiety from the human heart, it also protect it from being overwhelmed by agitation and agony.