How do we know Jesus Christ came in the flesh is true?

The declaration that 'Jesus Christ has come in the flesh' is pivotal in Christian doctrine, as it affirms both the divinity and humanity of Christ. This belief is vital to our understanding of salvation, emphasizing that Jesus was co-equal and co-eternal with the Father, as described in Isaiah 9:6. By taking on human flesh, He became our brother and identified with our nature, making His redemptive work on our behalf possible (Hebrews 2:14-18). Denying this truth leads to significant theological errors regarding Christ's nature and work.