A spiritual kingdom requires a spiritual nature, and in order to the acquisition of that the natural man must be regenerated (born again), divinely regenerated, for the creature can no more quicken himself than he can give himself a natural being. Why not? Because regeneration is no mere outward reformation, process of education, or even religious cultivation. No, it consists of a radical change of heart and transformation of character, the communication of a gracious and holy principle, producing new desires, new capacities, a new life. The new birth is absolutely imperative, but this is the work of the Spirit of God from the very nature of the case. Birth altogether excludes the idea of any effort or work on the part of the one born, hence it is written “It is the Spirit that quickeneth; the flesh profiteth nothing” (John 6:63).