(I got this little nugget from a Revive Our Hearts podcast as well!)
And we know that all things work together for good to those who love God, to those who are the called according to His purpose.
For whom He foreknew, He also predestined to be conformed to the image of His Son, that He might be the firstborn among many brethren.
Why does God work everything together for good? So we can be happy and avoid pain? Nope, so we can be conformed (you know, we die that He can live...we deny ourselves so we can walk by the Spirit...we change to line up with His standard...not always easy, fun stuff!) to the image of His son. Then the joy comes!