Christ's Sonship is in the Holy Trinity. The Lord Jesus said to His disciples: "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit" (Matt. 28:19). The use of the word 'name' in the singular form means that the Three are One. Because His Sonship to the Father is not a common sonship but a special One entailing His Divinity, He is called 'the Son'.