Heidelbasics: Brief Weekly Reflections on the Heidelberg Catechism by Rev. David Fagrey, Pastor of Grace Reformed Church of Rapid City, SD
33. Why is He called God’s only begotten Son, since we also are the children of God?
Because Christ alone is the eternal, natural Son of God, but we are children of God by adoption, through grace, for His sake.
“God so loved the world that He gave His only-begotten Son, that whoever believes in Him should not perish but have everlasting life” (John 3:16). Sons begotten [brought into existence by the process of reproduction] from parents “are properly called natural sons, to whom the essence and nature of their parents is communicated [not wholly but in part]” (Ursinus, 181). But the Son of God is eternal, as we have already proven in Question 25: Father, Son, and Holy Spirit are the one, true, eternal God. Thus, the Son of God, even before He became a man, has always been God’s only-begotten Son (John 17:5). In a manner that is altogether beyond our comprehension, the Father communicates the whole divine essence to the Son: “as the Father has life in Himself, so He has given the Son to have life in Himself” (John 5:26). “The Father has, therefore, communicated to Him the life by which He Himself lives by Himself… which life is that one and eternal Deity” (Ursinus, 181); “since the divine essence is infinite, indivisible, and not communicated in part… the Son has the whole essence communicated to Him, [and] He is, for this reason, equal with the Father, and consequently, true God” (Ursinus, 193). Jesus Christ is according to His eternal divine nature the natural and only Son of God.
The only way for sinners to become children of God is by adoption. God sent His Son into the world to die for our sins, so that God might, for His Son’s sake, confer upon us the right and title of the sons of God, which we forfeited in Adam (John 1:12; Luke 3:38). Before the foundation of the world, God “predestined us to adoption as sons by Jesus Christ” (Eph. 1:5). “God sent forth His Son, born of a woman, born under the law, to redeem those who were under the law, that we might receive the adoption as sons. And because you are sons, God has sent forth the Spirit of His Son into your hearts, crying out, Abba, Father!” (Gal. 4:4-6).
34. Why do you call Him our Lord?
Because not with silver or gold, but with His precious blood He has redeemed and purchased us, body and soul, from sin and from all the power of the devil, to be His own.
The title “Lord” means “master, owner.” In the Old Testament, a slave could be freed if a ransom were paid to his master. By our willful disobedience in Adam, we became “slaves of sin” (Rom. 6:20) and the devil (2 Tim. 2:25-26), as God’s just punishment for our sin. But Jesus Christ our Savior has redeemed us from the slavery of sin and Satan, by “giving His life a ransom for many” (Mark 10:45)–to fully satisfy God’s justice; “you were not redeemed with corruptible things like silver or gold… but with the precious blood of Christ” (1 Peter 1:18-19). Since His Church was “purchased with His own blood” (Acts 20:28), all believers belong to Him as His bondservants (Rom. 6:20-22). By the grace of His Holy Spirit we call Him LORD (1 Cor. 12:3), and are thankful to Him for our redemption. “For you were bought at a price; therefore, glorify God in your body and in your spirit, which are God’s” (1 Cor. 6:19-20).