How do we know Christ's teachings on loving enemies is true?

The truth of Christ's teachings is evidenced in His life and sacrificial death. As seen in Psalm 35:11-18, Christ faced false accusations and hostility throughout His life, yet He responded with humility and love. This demonstrates the perfect adherence to His own command to love one's enemies. Scripture assures us that Christ dealt graciously with us while we were His enemies (Colossians 1:21-22), which serves as both an example and a motivation for us to follow suit. Thus, the Christian duty to love one's enemies is grounded in the reality of Christ's redemptive work for sinners.