''...there is none else besides Him.'' [Va'Eschanan 4:35]
In truth, even the creations do not exist in their own right, as it appears to our eyes. We perceive it that way because we do not see Godly energy. However, from the perspective of the Godly energy which enlivens us, our existence is totally nullified into absolute nothingness, like a ray of light inside the globe of the sun.... Thus it follows that there is no existence at all other than that of God.
Even in the current period immediately preceding the true and complete Redemption, the way a person acts in day-to-day life should resemble life as it will be during the actual Messianic Era.
One of the most fundamental aspects of the future era is that there will be the fullest expression of the verse ''You were shown [the heavens] in order [for you] to know that God is God. There is none other besides Him''. i.e. it will be revealed throughout the entire world that ''there is none other besides Him'' - that there is no existence other than God.
It is this kind of feeling which is required too in our daily lives now: A person should feel literally, in every part of his life, that ''there is none other besides Him''. In other words, not only should one's worldly pursuits be done for the sake of a Godly purpose - i.e. that one feels the dichotomy between the ''worldly'' and the ''Godly'', but one nevertheless dedicates his worldly activities to a higher purpose.
Rather, one should feel the Godly identity of the world matters themselves. Consequently, he will not even become aware of any existence other than that of God, since he feels that ''there is none other besides Him''.
Freely translated from Sichas Simchas Torah 5752 - Lubavitcher Rebbe