Christ's work is effective because He perfectly fulfilled the requirements of the law and paid the penalty for sin through His death and resurrection.
The effectiveness of Christ's work is affirmed by several theological truths. Firstly, His death was a substitute for the sins of His people, fulfilling the law and God's requirements for righteousness (Romans 3:24-25). Furthermore, His resurrection serves as proof that God accepted His sacrifice and that sin's power was broken (1 Corinthians 15:55-57). Because of this, we can be confident that all for whom Christ died will be saved; His work is definitive and cannot fail. The scriptures assure us that all God's people have already been set free, thus validating the full and finished work of Christ.
Commentary