How do we know that false religion is wrong?

The Bible consistently warns against false religion, as seen in Revelation where Babylon symbolizes all forms of spiritual fornication. Scripture indicates that false religion operates on a mix of works and grace, which ultimately cannot save. Paul states in Romans 11:5-6 that if it is by grace, then it cannot be of works; otherwise, grace is no more grace. This blending of human effort with the gospel tarnishes the truth of salvation by faith alone in Christ alone. Believers are called to recognize and reject such deception, as it is a direct affront to God's sovereign mercy and the full atonement achieved by Christ.