How do we know Jesus was sinless?

The sinlessness of Jesus is a foundational belief in Reformed theology, grounded in Scripture. He was conceived by the Holy Spirit, which ensured that His humanity was free from the moral corruption that affects all descendants of Adam. For instance, Scripture states that He was 'that holy thing' (Luke 1:35). This intrinsic purity makes His role as our Savior possible, for He bore our sins while Himself remaining sinless, as underscored in passages like 1 Peter 2:22, which declares, 'He committed no sin, nor was deceit found in His mouth.' Consequently, His nature qualified Him to be our substitute in bearing the penalty for sin.