Faith is shraddha. Faith is the greatest thing in the world. Even the greatest philosopher has faith as his stronghold. No intellectualism can prove good if it is unsupported by faith. The whole world stands on faith, is guided by faith.
Religion has faith as its root. One cannot prove God if he has no faith in God. And this faith is the outcome of samskaras (past mental impressions). Faith is guided by impressions of actions done in previous births.
Blind faith should be turned into rational faith through understanding. Bhakti (devotion) is the development of faith. Jnana (self-knowledge) is the development of bhakti. Faith leads to the final experience. Whatever a person strongly believes in, that he experiences and that he becomes.
This whole world is a product of faithful imagination. If you have no faith in the world, the world does not exist. If you have no faith in sensual pleasure, you will not get pleasure from sensual objects. If you have no faith in God, you will never reach perfection. Wrong faith can even turn existence into non-existence. Faith is the fundamental necessity for spiritual sadhana (practice).
Aspiration is a development of faith. The flame of faith burns as the conflagration of spiritual aspiration for moksha (liberation). The devotee longs to have union with the beloved - he has no sleep, no rest. He always contemplates how to attain the object of his love. He prays, he sings, he gets mad with his Lord. Divine madness overtakes the devotee and he completely loses his personality in the aspiration for attaining God. This is called self-surrender.
You must have an ideal to live for - otherwise you will be heedless, depressed and negative. Understand well before you take a step. Have a clear-cut ideal and then have right attempt. Faith in God, faith in oneself, faith in the guru (preceptor), faith in the wise teachings, faith in all that is good and noble - this is the sap of life.