If everything is truly one and of the same nature as God, why do we need to do anything at all?
Having an intellectual understanding that everything is of the same essence as God, does not mean that one has understood experientially that this is true. In the same way that having an understanding that water is wet does not translate to having the experience of wetness. In actuality, until one has actually allow oneself to engage with the element of water, one cannot truly be said to have an understanding of what wetness is. The understanding prior to the experience is meaningless.
It is only after the experience occurs that an understanding of the experience can be useful; not before. One who asks this question is not seeking God. In actuality they are trying to find an excuse to not have to seek God. Unfortunately, most seekers are lazy, they do not want to engage in the necessary work needed to fully realize who they are.
Whether or not one needs to do anything for this realization is a different matter altogether. Yet hiding behind the philosophy of;
“since God is everything there is nothing I need to do to reach him since he is already present exactly where I am,”
is simply the mind cheating you out of your true self. What is needed is a sincere yearning to find out the truth of who and what you are at all cost. Without this yearning, nothing will come to fruition. One can meditate for years on end and only achieve “worldly success.” Meaning one will achieve a less stressful day, and have the tools to help the physical body remain more healthy and relaxed. Which is also an extremely beneficial and useful skill to have, but this is only a by product of the spiritual path and should not be seen as the goal.
The question one should ask oneself is;
“is having this understanding giving me what I started out on this path for?”
Why did you start this journey in the first place. This point should be clarified, for it will save you a lot of trouble and frustration along the way.
Everything is fundamentally of the exact same nature as God. Yet, unless this is realized via direct experience, having this knowledge will not be beneficial.