1. The mitzvah of Emuna – to believe that there is one G-d Who made, makes, and will make everything that exists. Everything which exists now, or existed in the past or will exist in the future forever is His will and exists because He wants it. And, He brought us out of Egypt and gave the Torah to us. And this is an active commandment, as the Torah says, “I am the L-rd your G-d Who took you out of the land of Egypt, from the house of slavery.” The meaning of this is, “You must know and you must believe that there is a G-d of the universe Who supervises, just as He took you out of Egypt.”
2. The mitzvah never believe in any other god – the Torah says, “You will not have any other gods besides Me.” Even if one acknowledges that the Holy One blessed be He is the ruler over everything, except he will imagine in his mind that He turned over the management of the universe to an angel or a star, this is succumbing to idolatry and violates “You will have not have any other gods besides Me.” Instead, each person must believe that the Holy One blessed be He alone personally supervises everything in existence everywhere and that everything else is a creation which has absolutely no power to do anything without His will.
3. To attribute oneness to Him – as the Torah says, “Hear, Israel, the L-rd is G-d, the L-rd is one.” The meaning of this is that, “Hear, Israel, and know that it is Hashem Who caused everything in existence to be. He did this with His will and He is our G-d Who supervises everything everywhere in existence. He is One G-d without any partners.”
4. To love Hashem – as the Torah writes, “And you will love the L-rd your G-d with all your heart…”. And how will a person come to achieve this love? Through Torah. Through contemplation in Torah, a person will recognize the greatness of the Holy One blessed be He. The point of this mitzva is that a person should channel all of his thinking into the love of Hashem, may He be blessed. And he will cause his heart realize that everything that there is in the universe, whether wealth or children or honor, is all the worthless in comparison to the love of G-d, may He be blessed. The person who devotes his energies and thoughts to materialistic matters and worldly futilities, not being for the sake of Heaven, but rather to please himself and attain honor, nullifies this active commandment.
5. To fear Hashem, in order to remain free of sin. On this the Torah says, “Fear the L-rd your G-d.” When a sinful thing will come to a person, he is obligated to arouse his spirit and remember that the Holy One blessed be He is the Supervisor of all deeds of every human being and privy to our thoughts and speech as well as to our deeds.
6. Not to stray after the lust of the heart or the sights of the eyes – the Torah says, “And do not go straying after your hearts and after your eyes.” Our Talmudic sages said, ‘After your hearts’ means heretical ideologies, and ‘after your eyes’ means improper images. This necessitates a constant reinforcement of emuna and guarding of the eyes.
(Mishna Brura Siman 1 – Translation Rabbi Brody)