God wants to be your friend because He likes you. It makes Him happy to be your friend. Another reason that He wants to be your friend is because He wants to help you be happy. He wants to help you with your probems and he wants to give you interesting things to do that will make you feel joyful and at peace.
Do you have a pet that you like? If so, why do you like that pet? Is it because that pet makes you feel happy. Do you enjoy making your pet happy, too by taking care of it and finding fun things for it to do? Then you understand just a little bit about how God feels about you.
Or maybe you really enjoy playing computer games. Why do you like them? Is it because playing them makes you feel happy? Well, that is how God feels about being your friend.
“He will take great delight in you.” Zephaniah 3:17