“He who did not spare His own Son but gave Him up for us all, how will He not also with Him graciously give us all things?” Romans 8:32
God is good, and everything in Him is good. Therefore, He cannot give something that is outside of His nature. He can only give good things and He intends to give us all good things.
If God has given us the hardest thing He can give, namely His beloved Son, then He can give us the easy ones, “all things.” But, these “all things” mean all the things that are good for us. They don’t mean everything that we want and desire but they meant the things that we really need to be conformed to the image of His Son. These are the things that we need to attain eternal joy, and that is in His Presence.
Christ’s death and resurrection assure us that God will give us everything we need to do His will and give Him glory, and thus attain eternal joy.