God possesses all joy and happiness. It is his will for us to have all that he has. While he can give you some things (such as your mortal life) without any action on your part, the majority of what he has to give you can only be received through your choice. He is not limited in what he is willing to give, but you are limited in what you are willing to receive.
We can receive God a little, a lot, or not at all. For example, when the Lord visited his followers after his resurrection, he delivered many teachings and blessings. Still, he had to stop short of all he had to give because they were not able to receive it:
2 I perceive that ye are weak, that ye cannot understand all my words which I am commanded of the Father to speak unto you at this time.
3 Therefore, go ye unto your homes, and ponder upon the things which I have said, and ask of the Father, in my name, that ye may understand, and prepare your minds for the morrow, and I come unto you again. (3 Nephi 17)
Why have you not yet received all that he has? He said: “...I will order all things for your good, as fast as ye are able to receive them. Amen.” (D&C 111:11) He is not the arbiter of what you receive—you are.