"If this man were not from God, he could do nothing."
People come and people go. Nations and empires rise and fall. However, there comes a day when the entire world will fade away like a dream to be forgotten. The only person who actually does anything productive on earth is the one who also can bind in heaven what he binds on earth. It is the one who, while living in the Mortal realm, can effect the Eternal and can usher in the Heavenly Realm into the Earthly one. A truly productive person is an intersection of two worlds; a place where Heaven and Earth meet. They are the temple of the Holy God.
And apart from Him, they can do nothing, nothing that lasts anyway.
It is only those who believe and trust in Christ and have received the Holy Spirit into their hearts who are the only ones able to accomplish anything good. There are those who seek to do good apart from God but nothing they do has any lasting impact. None of it has real value. They labor in vain. If you rescue a drunkard from the bottle but fail to save him from the sinking ship, have you really done anything at all? Such are those who work for social concerns but ignore the spiritual. If we are not about winning souls to the Great Banquet, we are not about anything at all. If not for God, we could do nothing at all.