WSC Q.45: Which is the first commandment?
The first commandment is, Thou shalt have no other gods before me. (Exod. 20:3)
WLC Q.103: Which is the first commandment?
The first commandment is, Thou shalt have no other gods before me. (Exod. 20:3)
WCF 21.2.
Religious worship is to be given to God, the Father, Son, and Holy Ghost; and to Him alone; (Matt. 4:10, John 5:23, 2 Cor. 13:14) not to angels, saints, or any other creature: (Col. 2:18, Rev. 19:10, Rom. 1:25) and, since the fall, not without a Mediator; nor in the mediation of any other but of Christ alone. (John 14:6, 1 Tim. 2:5, Eph. 2:18, Col. 3:17)