I think the question should be answered by all those who has the main roles in one's existence . God , parents , myself
Talking on my parents side , I think having children is one of the life enjoys , parenting is an instinct and inner need inside everyone , if not on children may be on pets.
From God side , I think he created humanity because he wanted to love and to be loved and interested in, to parent and taking care of people, its God's essence to practice love and parenting, but gave us the free will and mind to choose it ourselves , and let us define what each individual purpose in life.
My purpose in life is to live with all who I love , build my own relationship with God.
And enjoy the seeking for him.