Faith
How can one increase in faith?
You must strive. A child does not know, in learning he obtains knowledge. search for Truth.
There are three kinds of Faith: first, that which is from tradition and birth. For example: a child is born of Muḥammadan parents, he is a Muḥammadan. This faith is weak traditional faith: second, that which comes from Knowledge, and is the faith of understanding. This is good, but there is a better, the faith of practice. This is real faith.
We hear there is an invention, we believe it is good; then we come and see it. We hear that there is wealth, we see it; we work hard for it, and become rich ourselves and so help others. We know and we see the Light, we go close to it, are warmed by it, and reflect its rays on others; this is real faith, and thus we receive power to become the eternal sons of God.
Healing
‘Abdu’l-Bahá said: Disease is of two kinds: material and spiritual.
Take for instance, a cut hand; if you pray for the cut to be healed and do not stop its bleeding, you will not do much good; a material remedy is needed.
Sometimes if the nervous system is paralyzed through fear, a spiritual remedy is necessary. Madness, incurable otherwise, can be cured through prayer. It often happens that sorrow makes one ill, this can be cured by spiritual means.