Jesus was not always a man. His divine nature was joined to a human nature through the miracle of his conception. A word theologians invented to describe this unique event is “hypostatic union“.
His miraculous birth was prophesied 800 years before His coming (Isaiah 7:14)
The prophecy was fulfilled in Mary (Luke 1:30-31)
Jesus did human things like getting tired (John 4:6), thirsty (John 19:28), ate food (Luke 24:40-43), showed emotion (Mark 6:34), cried (John 11:35), was tempted (Hebrews 4:15), and died (John 19:30).