Why is the work of the Holy Spirit essential in salvation?

The work of the Holy Spirit is a critical aspect of salvation as He is the agent of regeneration. According to 1 Peter 1:23, believers are born again 'not of corruptible seed, but of incorruptible, by the word of God.' The Holy Spirit transforms the sinner's heart, granting them the ability to believe and trust in Christ, which is essential because sinners are dead in their transgressions and cannot save themselves. The Holy Spirit not only imparts a new nature but also enables the believer to live a life of faith and holiness. This divine work ensures that salvation is a complete act of God, underscoring the necessity of the Holy Spirit in effecting salvation in the life of a believer.