Why is fighting against self-righteousness important for Christians?

For Christians, battling self-righteousness is vital because trusting in one's works leads to spiritual pride and distance from God. The sermon explains that self-righteousness must be killed to keep believers reliant on Christ for salvation. As stated, 'Man's will has got to be killed... all of self must die so that we can live in Christ.' This reliance on the grace of God, rather than our perceived righteousness, ensures that we uphold the doctrine of salvation by grace through faith.