The Heidelberg Catechism

But why art thou called a Christian? [102]

Because I am a member of Christ by faith, [103] and thus am partaker of his anointing; [104] that so I may confess his name, [105] and present myself a living sacrifice of thankfulness to him: [106] and also that with a free and good conscience I may fight against sin and Satan in this life [107] and afterwards I reign with him eternally, over all creatures. [108]