There are many false "christians" who will tell you he was just a man, but as for true Christianity we realize that he was God almighty in the Flesh as told to us in the Holy Scriptures. Thank you with Love in Christ.
He's certainly nor a metaphor. He spoke, made demands, and performed works. There is historical documentation of His existence. You could argue that He was not the son of God, but He did exist as a living man.