Because whom he foreknew, he also predestined to be of similar nature of the form of his Son, in order for him to be the firstborn son among many brothers.
They shall come with weeping. And I will lead them with supplications. I will cause them to walk by rivers of waters, in a straight way in which they shall not stumble. For I am a father to Israel, and Ephraim is my firstborn.
But I said, How I will put thee among the sons, and give thee a pleasant land, a goodly heritage of the hosts of the nations! And I said, Ye shall call me My Father, and shall not turn away from following me.