How do we know the Holy Spirit is essential for salvation?

The importance of the Holy Spirit in salvation cannot be overstated. He is the one who applies the benefits of Christ's redemptive work to the believer. Without the Holy Spirit, individuals are spiritually dead and unable to seek God. John 3:3 emphasizes the necessity of being born again to see the kingdom of God, highlighting how the Holy Spirit quickens us to spiritual life. Additionally, Romans 8:9 states that if anyone does not have the Spirit of Christ, they do not belong to Him, further affirming the indispensable role of the Holy Spirit in the process of salvation.