How do we know that Christ's death was effectual for salvation?

The effectual nature of Christ's death for salvation is fundamentally affirmed by examining the intentions and accomplishments of the cross. According to Isaiah 53:11, 'My righteous servant shall justify many, for he shall bear their iniquities.' This verse illustrates the direct correlation between Christ bearing sin and the justification of those He died for, reinforcing the notion that His sacrificial death was not in vain. Rather, it was designed by divine decree to guarantee salvation for the elect, ensuring that none for whom He died would face eternal damnation. This understanding aligns with the Reformed principle of limited atonement, which posits that Christ’s redemptive work is specifically effective for those who are chosen in Him. Thus, the certainty of salvation stems from God's unchanging purpose and the perfect efficacy of Christ’s atoning sacrifice.