Mark 1:3

John the Baptist was the voice of one calling in the wilderness, urging people to prepare for the Lord's coming. In the book of Isaiah, this prophecy speaks of the coming of the Lord, the God of Israel. Here, it refers to the Lord Jesus (see 12:35–37). The early church called itself "the Way," likely referring to this promise (see Acts 9:2; 19:9, 23; 22:4; 24:14, 22; compare Acts 2:28; 18:25–26; Romans 2:20; 2 Peter 2:2, 21).

• Mark includes Old Testament prophecies (messages from God given long ago) to support his account of the good news about Jesus Christ. John the Baptist’s role as a prophet and messenger shows that Jesus is the promised Lord and king. He is the Christ (or Messiah, God’s chosen one) and the Son of God.

• Isaiah: Mark follows the Jewish practice of mentioning only the best-known source in a quotation. Here he names Isaiah, even though the quotation also includes (Malachi 3:1; Isaiah 40:3).

This account does not focus mainly on John the Baptist, the messenger. Instead, it is about the one whom he announces as Jesus the Messiah, the Son of God (1:1).