Why Do We Need G-d?

When asked this question, I usually answer with a question, "Why do you think you exist?". To be certain, the reason we are here is to take part in a greater plan that we attribute to a higher power that helps answer the questions we cannot until the real answer is revealed through the creative process we are seemingly designed to accomplish. We do not need someone to blame for things but rather thank for the experience and the ability to grow. 
G-d Listens and Talks to Us
Sometimes we need something other than human interaction to help figure out what we did and also to confess what we know we did wrong in order to make amends and fix it. We need G-d to help us gather the mental strength to not make the same mistakes again. God told Cain that we have the capability to master the evil within when He said,
"Surely, if you do right,
There is uplift.
But if you do not do right
Sin couches at the door;
Its urge is toward you,
Yet you can be its master.” (Genesis 4:7) 
Why We Need Boundaries
We were given categories of Laws to mark the boundaries between our good and evil inclinations. Unfortunately, there are people who take this to an extreme and creation goes backwards instead of forwards through committing atrocities that cause a recreation to take place. We also have people that take our human form and perform experiments that are not supposed to be such as changing our biological makeup resulting in a change from female to male and vice versa. The other extreme is to test our capacities for learning and what boundaries are set for our existence. Sometimes we experiment to test our human boundaries for strength or immunity capacity. We also experiment with the capabilities of the mind. 
We would not be able to do any of this if it was not part of the process for the greater good of mankind. We need G-d so we can understand the boundaries in which we can have creative freedom. Without this, ultra curious people would test personal ideologies that might be outside our understanding and cause a corruption which could end us. 
We need an understanding of a higher power that tests our strengths and weaknesses. We need to trust that this higher power will not let us fail when we fall. We need the moral and ethical boundaries so that we do not take ourselves to places we do not need to be. We need to be kept in check. 
We Are Responsible For Our Own Faults and Actions
Do we need someone to stand before the creator in our defense? Actually no, we don't. The Scriptures state that G-d does not want anyone to be responsible for His creation but the creation itself. Can a person step in to save another? Physically and mentally, yes. We have people that that is their job specifically but no one stands before G-d to answer for another's actions and words while on this earth. We are responsible for how our Spirit meets the Maker. He will judge us and cleanse us. 
Will We Ever Not Need G-d?
No one knows what will truly happen next. We have multiple ideologies out there but no one is privy to that info. We can hope and guess what may come but only G-d knows the outcome of the plan. I personally believe we need G-d because He is who He is (there really is no other explanation). We are not here by chance, too many possibilities and coincidences tell us we were at some point created in an image that is both physically and mentally based on a design for some greater good. We were created to grow into something even better than we are today. We were created to evolve into what G-d needs us to be. 
Grow with G-d and you will see a change for the better. Trust is G-d means you are actively taking part in His overall plan. 
​Rob, His Servant