What does Travailing in the Spirit mean? Paul the Apostle did this on behalf of others!?

It means to travail as in giving birth! Just as a woman in the natural travails when she is about to deliver her child, Christians also prevail in the spirit, to also give birth to someone whom God is calling into the Kingdom. Believe this that when you are I, or any Christian who has been born again, someone, somewhere travailed and Birth us into the kingdom of God.. Many Christians are still on the milk of God's word and do not even know that this too is the reason that they are chosen...Very Good question!!