Is there a symbiotic relationship between our spirit and our soul? In some respects, the answer is yes. Without our spirit (which belongs to God) we would not be able to communicate as effectively as we can with God.
Think of the spirit as not only a living being within you, but also a transmitter. When you pray, the spirit relays that prayer into the spirit realm. The spirit is also a recording device. It records events in your life that will make you or break you, as at judgment the recordings will be played back and you will be judged on the contents of them.
When you leave this world your spirit will return to Heaven, where it was created and where it will always be. Your soul, on the other hand, will stay here in this world awaiting the return of Jesus... you will "sleep". When the Judgment comes your soul will be in the presence of Jesus, God, and that old familiar spirit which will be playing its tape back.
My life without God is not one I am proud of and I am not looking forward to answering for my crimes against God. But I have accepted Jesus Christ and he is my protector. Since accepting the Lord, I have been blessed over and over again. I continue to be blessed every day, from work to love. I am truly awed by our Lord.