Longer Catechism (Orthodox) 1.60

Chapter 1 — Introduction

Section 60. Q. How do miracles serve for a sign that the word spoken is from God? A. He who does true miracles works by the power of God; consequently he is in favor with God, and partaker of the divine Spirit; but to such it must belong to speak only the pure truth; and so, when such a man speaks in God's name, we are sure that by his mouth there speaketh really the Word of God. On this account our Lord Jesus Christ himself owns miracles as a powerful testimony to his divine mission: The works which the Father hath given me to finish, the same works that I do, bear witness of me, that the father hath sent me. John v. 36.