Heidelberg Catechism

Question 78. Are the bread and wine, then, changed into the actual body and blood of Christ?
Answer: No. Just as the water of baptism is not changed into the blood of Christ, nor is it the washing away of sin itself, but is simply God’s sign and confirmation, (a) so too the bread in the Lord’s supper is not changed into the actual body of Christ, (b) although it is called the body of Christ Jesus (c) in keeping with the nature and language of sacraments. (d)
(Scriptural proofs after the fold.)