Why does God need us and what was His ultimate reason for creating us?

Question:
Why does God need us and what was His ultimate reason for creating us?

Answer:
If I may, I would like to add a brief, belated thought to the very good and full answers already given. I’ve wondered about this question for some time. I believe that we have indeed been told in Scripture of the ultimate Reason behind all of God’s thoughts and purposes and actions.

That Reason is that “God is Love” (1 John 4:8, 16)!
Of course, love is infinitely, eternally, and perfectly satisfied and fulfilled between the three divine Persons of the Godhead. But He (the Three are One) will not contain that love or confine it solely to God alone. God’s love, by His will, overflows in a flood to others, His created beings.
No, He doesn’t need us. Instead, He created us, and then redeemed us, in order to bless us with a wonderful ability to love. The cross of Christ is the ultimate display of the love of God. “We love…because He first loved us” (1 John 4:19). Therefore, when we love (give, sacrifice) in our small measure we partake of the blessings of loving that He enjoys.
Jesus sums it up nicely by saying, “It is more blessed to give than to receive” (Acts 20:35). This is not just some proverb your grandmother made up. It is a simple, but most profound, statement of the mind of God. When we respond to His love, we love, voluntarily giving (sacrificing): our heartfelt worship, praise, and thanksgiving (Hebrews 13:15); our love and affections for the Father and the Son (john 16:27); and all believers (1 Peter 1:22); our bodies (Romans 12:1,2); and our belongings for His service and for one another (Hebrews 13:16).Isn’t this the grand “Why” behind the grand purpose, plan, and glorious outcomes already presented in the last issue? God is Love! That’s why.