How do we know that Christ is fully God and fully man?

The biblical narrative presents Christ as both fully God and fully man, a doctrine known as the hypostatic union. John 1:1 states, 'In the beginning was the Word, and the Word was with God, and the Word was God,' affirming His deity. Simultaneously, John 1:14 declares that this Word became flesh. This simultaneous existence of divine and human natures is crucial, as it establishes Jesus as the perfect mediator who can understand human vulnerability while also possessing divine authority. Scripture consistently reinforces this dual nature throughout both the Old and New Testaments, revealing Christ as the sovereign Creator and the suffering servant.