The Full Deity And Humanity of Christ
"We confess therefore, that God has fulfilled the promise which He made to the fathers by the mouth of His holy prophets, when He sent into the world, at the time appointed by Him, His own only-begotten and eternal Son, who took upon Him the form of a servant and became like unto man, really assuming the true human nature with all its infirmities, sin excepted; being conceived in the womb of the blessed virgin Mary by the power of the Holy Spirit without the means of man; and did not only assume human nature as to the body, but also a true human soul, that He might be a real man" (Art. XVIII). Or, that "God's eternal Son, who is and continues true and eternal God, took upon Himself the very nature of man of the flesh and blood of the virgin Mary, by the operation of the Holy Spirit, that He might also be the true seed of David, like his brethren in all things, sin excepted" (Heidelberg Catechism, Lord's Day XIV).
Reformed Theological Institute believes:
