How do we know that faith in Christ is essential for salvation?

The necessity of faith in Christ for salvation is underscored in John 10:9, where Jesus states, 'I am the door; by me, if any man enter in, he shall be saved.' This indicates that Christ is the appointed means of salvation for all who would believe in Him. The Reformed perspective teaches that faith is not earned but granted by God, and thus it is a part of His sovereign plan of salvation. This leads us to understand that being saved is an act of faith in Christ, received graciously and not through human endeavors. Paul also emphasizes this in Ephesians 2:8-9, highlighting that we are saved by grace through faith, not of ourselves.