We often say of the Lord Jesus that He is fully man and fully God. Although it may be hard to grasp, the truth is that Christ is completely man and is completely God. You ask an interesting question. Was Jesus God even when He was a child? Let’s consider the words of the angel to Mary in Luke 1:35, “And the angel answered and said unto her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also THAT HOLY THING which shall be born of thee shall be called the Son of God.” It could never be said of a mere man that he was holy. It is the man/God, Christ Jesus that is called holy at birth. Not just innocent or sinless, but HOLY!

The angel of the Lord spoke to Joseph in a dream, telling him, “Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost. And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins. Now all this was done, that it might be fulfilled which was spoken of the Lord by the prophet, saying, Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, GOD WITH US.” (Matthew 1:20-23). His very name of Emmanuel shows that God was with them in the person of this little babe.

We read in Matthew 2:1-2, “Now when Jesus was born in Bethlehem of Judaea in the days of Herod the king, behold, there came wise men from the east to Jerusalem, Saying, Where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him.” Even these foreign wise men knew that Jesus at birth was the King of the Jews. Indeed He was “King of Kings and Lord of Lords!”

While we do not know a lot about the Lord as a child, we are told of events in His life from His birth until He was a 12-year-old boy. Luke, chapter two tells us of events in the early life of the Lord Jesus. We are not told about the Lord from the time he was 12 years old until He began His public ministry when He was around 30 years old. However, when He was 12 years old, we read “And Jesus increased in wisdom and stature, and in favour with God and man.” (Luke 2:52). As the Lord grew, His wisdom increased as His body grew into a man. As the Lord was always obedient to His Father (read John 8:29), He increased in favor with Him and with those around Him who must have marveled at this wise, obedient young man. (312.5)