The calling is not just the naming but is the effecting of us as SonsOfTheHolySpirit. It is when our words and actions proceed from the transformed Mind and HolySpirit unction that our calling is effected.
The glory of Christ is what He willed and accomplished for us by enduring the cross and raising Himself from the dead - sonship in the NewBirth by His HolySpirit as joint heirs of all that the Father has.
What world is John talking about?
He is talking about the people on earth who are CarnalMinded having never received the Gospel of Jesus Christ.
Those who are CarnalMinded cannot understand those who have become SpiritualMinded by receiving the Truth and being BornAgain.