This document discusses the key biblical concept of justification. It defines justification as being declared righteous by God, not based on human works but through God's grace by faith in Christ. It explains that through justification by faith alone in Christ's sacrifice, believers are completely forgiven, given a new righteousness, and declared not guilty and free from condemnation. The purpose of studying justification and other biblical terms related to salvation is because many Christians do not understand them, which leaves believers vulnerable to temptation, and sound teaching produces strong Christians.