Rav Volbe Ztl states in his book, Ali Shur, that emunah (active faith) is a reality, not a concept.  It is the purpose of creation and the foundation of existence.  It’s our life preserver to which we cling with a vice like grip.

Emunah is actually a way of thinking. A person who looks at the world with the mindset of Emunah looks for the Hashgacha Pratis (Divine Providence) in everything.  He sees Hashem in “Nature” and in every historical event.

Emunah is the opposite of blind faith.  It’s a perspective of being able to see things with a perfect clarity because Emunah is not an intellectual conclusion. Navuah (Navi) means to be able to see Hashem, and Emunah is a piece of navuah.

It comes out that a ba’al Emunah (the one who masters Emunah) is a person that knows with a certainty that Hashem is here, which culminates in a palpable feeling of living with Hashem. 

The meaning of this world as seen through eyes of Emunah is to turn fate into destiny.  By seeking Hashem,you are acknowledging Ein Od Milvado (there none one but HaShem), that there is nothing other than Hashem. 

Emunah tells us that there are no accidents in this world, knowing that HaShem allows what seems to be bad for our ultimiate good! HaSatan, or demons do not have permision to attack us without express permision form HaShem, this is also part of emunah, and that because we have an open door, which HaShem want us to close (via teshuva / repentance) and this is why he allows them to bother us within limits, and we learn that even this is for the ultimate the best!

The Gemara (Chullin 7b) quotes the statement of Rabbi Chanina ben Dosa, that the words "Ein Od Milvado" exclude even the powers of keshafim – sorcery. Once, the Gemara relates, a sorceress tried to take some earth from under Rabbi Chanina’s feet, in order to cast a spell over him. "Go ahead," said Rabbi Chanina, "it will do you no good – for it is written, Ein Od Milvado!"

Rabbi Chaim Volozhiner (Nefesh HaChaim 3:12) explains that Rabbi Chanina was not relying on a miracle to save him. Rather, Rabbi Chanina, "had firmly established in his heart the emunah [belief] that there is no other force in the universe other than the will of HaShem. He was so connected in his mind to the Master of all forces that it was clear to him that nothing else has any control or existence at all. With this conviction, he was confident that the forces of sorcery could have no influence over him – unless HaShem so desired." When he declared, "Ein Od Milvado," he was emphasizing the clarity of his perfect faith.

For by grace you have been saved through faith; and that not of yourselves, it is the gift of G-d. (Ephesians 2:8) For there is one G-d, and one mediator also between G-d and men, the man Yeshua the Messiah. (1 Tim. 2:5) 

Ein Od Milvado – HaShem echad, uShmo echad!