Zac Poonen emphasizes the 'Spirit of Sacrifice' by drawing parallels between Abraham's willingness to sacrifice Isaac on Mount Moriah and the sacrificial love of Jesus on Calvary. He highlights that true service to God and the building of His church requires selfless sacrifice, contrasting it with the self-serving attitudes prevalent in society today. Poonen illustrates that just as a mother sacrifices for her child without expectation of return, believers must adopt a similar attitude towards the church. He challenges listeners to reflect on their commitment to God and the church, urging them to embrace a life of sacrificial love. Ultimately, he calls for a wake-up to the reality that God's work is accomplished through those who embody the spirit of sacrifice.