How do we know that sanctification is essential for salvation?

The Bible teaches that sanctification is a critical component of salvation, as seen in 2 Thessalonians 2:13, where Paul links it directly to belief in the truth. This sanctification is the work of the Holy Spirit, who opens the eyes of the spiritually dead to see and accept the truth of the Gospel. This inward transformation is necessary for anyone to come to faith in Christ, as it aligns with God’s purpose of drawing His elect unto Himself, affirming that genuine faith and repentance are gifts given by God rather than merely human actions.