When does the Holy Spirit come to indwell and regenerate a believer?

Les explains that the old Adam is still present experientially in everyday life, though the new nature is imparted by a divine act of God. At the very same time the new nature becomes a reality, the Holy Spirit comes in, indwells, takes up residence, and regenerates our spirit—which in Adam's case died the moment he sinned. The Holy Spirit then agrees with our spirit, restoring fellowship with God through the Spirit. The Spirit working on our spirit influences the new nature, which in turn controls the acts of the physical body. As believers are led by the Spirit, the body aligns with God's laws that are good for society, family, and marital relationships. Humans still sin.