How do we know that faith and repentance are true doctrines?

The interdependence of faith and repentance is grounded in biblical theology, where both must exist simultaneously for genuine conversion. Acts 11:18 indicates that repentance is a gift from God granted unto life, emphasizing that true faith involves a turning from self-righteous striving to trusting in Christ alone for salvation. This perspective rejects the idea of being saved by one's decision or acts, thus underscoring that genuine faith inherently involves an acknowledgment of sin and a turning to Christ. Both elements work in unity, akin to two sides of a coin, as no one can possess one without the other.