What does the Bible say about fulfilling all righteousness?

In Matthew 3:15, Jesus states, 'Thus it becometh us to fulfill all righteousness.' This phrase encompasses the idea that through His fulfillment of the law, every believer is also considered to have fulfilled all righteousness because they are united with Christ. When Christ obeyed the law, it was not merely an act for Himself but a representation of all those who are His. This is rooted in the theology of union with Christ, where every aspect of His obedience is credited to believers—the same way Levi paid tithes through Abraham because he was in his loins (Hebrews 7:9-10). Therefore, through faith, believers can claim the fulfillment of all righteousness accomplished by Christ as their own.