Place yourself now, in Nazareth. You are standing beside the road, across the way from where Mary and Joseph live. A toddler is wobbling back and forth in the first days of his learning to walk. He stumbles and falls to the ground. His mother runs to his aide and picks him up, dusting off the dirt from where he has fallen. Suddenly you realize, this is the Son of God, the One who made all things that exists. He has not always been a human being. He has not always been a tiny boy. He was and is the King of the Universe, the Creator and Sustainer of all things.
He walked the halls of heaven, but now He must learn to walk as a child. He has spoken the universe into existence, but now He must learn to talk for the first time as a human being.
It appears that the plan of God for His Son, was that He would need to understand everything that all men go through in their life. From normal birth, infancy, into the teen years and adulthood, our Savior would need to experience what it is like to be one of us. Jesus went through every circumstance that we will go through in our life. He understands what it is like to live as a human being in this world. This is why He is not only able to die in our place, but He can also perfectly sympathize with all of the struggles and difficulties that we feel as we live in a fallen world.