How do we know believers are called saints?

In Philippians 1:1, Paul addresses the recipients of his letter as 'all the saints in Christ Jesus.' This designation is not based on their moral perfection but rather on the sanctification they have received from God. Saints are those who have been set apart for God’s glory through His divine election, the sacrifice of Christ, and the regenerating work of the Holy Spirit. Paul repeatedly emphasizes that every believer, regardless of their past sins, is made holy in God's sight because they are sanctified by Christ's blood and called into fellowship with Him.