The Existense of Satan
"He also created the angels good, to be His messengers and to serve His elect; some of who are fallen from that excellency in which God created them into everlasting perdition, and others have by the grace of God remained steadfast and continued in their first state. The devils and evil spirits are so depraved that they are enemies of God and every good thing… and are, therefore, by their own wickedness adjudged to eternal damnation" (Art. XII). But "man, through the instigation of the devil, by his own willful disobedience, deprived himself and all his posterity of these gifts" (Heidelberg Catechism, Lord's Day IV).
Concerning the historical fall of man into sin, "We believe that God created man out of the dust of the earth, and made and formed him after His own image and likeness, good, righteous, and holy . . . but (man) willfully subjected himself to sin and consequently to death and the curse, giving ear to the words of the devil" (Art. XIV). "We believe that through the disobedience of Adam original sin is extended to all mankind. . ." (Art. XV).
Reformed Theological Institute believes:
