How do we know salvation is through union with Christ?

Romans 6:3-4 illustrates the essential doctrine of union with Christ in salvation. When believers are said to be 'baptized into Christ,' this refers to their identification with Him as their representative. Just as sin entered the world through Adam, resulting in condemnation for all, those who are united with Christ share in His obedience, His death, and His resurrection. Therefore, when Christ died, believers died too; when He was raised, they were raised to newness of life. This vital union with Christ not only assures salvation from sin's penalty but also empowers believers for a transformed life in service and sanctity. It highlights the truth that all spiritual blessings are found in this union.