How do we know Jesus was both God and man?

The mystery of the incarnation reveals that in Jesus Christ, the divine and human natures are united without confusion. Hebrews 2:10-14 explains that to save His people, Christ took on human nature, becoming like His brethren in all things, yet without sin. He represents the ultimate mediator between God and man because He is fully God, embodying the divine attributes, and fully man, experiencing human frailty and suffering. This dual nature allows Him to effectively redeem His people, fulfilling the requirements of the law while being capable of bearing their sins.