You shall love the ETERNAL your God with all your heart and with all your soul and with all your might.

Revere only the ETERNAL your God; worship [God] alone; swear only by God’s name.

(1) It is a mitzvah to love and fear this glorious and awesome God, as [Deuteronomy 6:5] states: "And you shall love God, your Lord" and, as [Deuteronomy 6:13] states: "Fear God, your Lord."

One verse says, “you shall love the Eternal, your God,” and another verse says, “fear the Eternal, your God, and Him you should serve.” Act from love and act from fear. Act from love, because if you are tempted to hate, know that you must love and a lover is no hater. Act from fear, because if you are tempted to rebel, know that you must fear and one who fears does not rebel.

ובשמו תשבע AND THOU SHALT SWEAR BY HIS NAME — If thou hast all the characteristics mentioned here, i.e. that thou reverest His name and servest Him, then thou mayest take an oath by mention of His name, for just because thou reverest His name, thou wilt be cautious with thy oath; but if not, thou shalt not so swear.

THOU SHALT FEAR THE ETERNAL THY G-D. The purport thereof is that after he commanded concerning the love of G-d, he mentioned that [one is] to fear Him so that he not sin and be punished.

THOU SHALT FEAR. You shall not violate any of the negative commandments.

SHALT THOU SERVE. By observing the positive commandments.

(2) What is the path [to attain] love and fear of Him? When a person contemplates His wondrous and great deeds and creations and appreciates His infinite wisdom that surpasses all comparison, he will immediately love, praise, and glorify [Him], yearning with tremendous desire to know [God's] great name, as David stated: "My soul thirsts for the Lord, for the living God" [Psalms 42:3].
When he [continues] to reflect on these same matters, he will immediately recoil in awe and fear, appreciating how he is a tiny, lowly, and dark creature, standing with his flimsy, limited, wisdom before He who is of perfect knowledge, as David stated: "When I see Your heavens, the work of Your fingers... [I wonder] what is man that You should recall Him" [Psalms 8:4-5].
Based on these concepts, I will explain important principles regarding the deeds of the Master of the worlds to provide a foothold for a person of understanding to [develop] love for God, as our Sages said regarding love: "In this manner, you will recognize He who spoke and [thus,] brought the world into being."

It is a well-known fact that everyone who loves also reveres. There are people who do revere but do not love the object of their reverence. This teaches that reverence is an aspect of love. This is what Moses said here when he wrote; “fear the Lord your God, after he had already written in the קריאת שמע that we are to love the Lord our God.”