How do we know that faith is needed for salvation?

The doctrine of justification by faith is deeply rooted in Scripture, especially in Romans 4, where Paul uses Abraham as an example. Abraham was declared righteous not by works but through his faith in God. This foundational truth establishes that all believers must rely on faith to be justified before God. As Paul articulates in Galatians, the law cannot justify us; only faith in Christ can do so. This underscores the importance of faith as the means by which we are united to Christ and receive righteousness, confirming that salvation comes by grace through faith.