The life of a Christian is quickened, his flesh is mortified. Vampyres, as the living dead, tend to rot a bit. Jesus can change form, appearing as light, or a piece of bread. Vampyres can change form. Christians must convert others.
Christians detest mortal existence.
So do vampyres. The stake is not always effective in killing vampyres as some are strong enough to remove them and use them against their attackers. The Last Days of Christ the Vampire, written by J. G. Eccarius. It's a fast paced novel with Christ as the ultimate vampyre, taking over the world with a viral belief system. I am that bread of life.