John the Baptist, forerunners, roadies, Mark 1, Gospel of Mark, Isaiah 40, Advent, waiting, repentance, Beginnings, Jesus Christ the Son of God, Backstory, Fulfilled prophecy, New Exodus, wilderness, baptism, forgiveness, Repent, exalting Jesus, baptism of the Holy Spirit, Good news, Gospel, slow down, listen to God's voice, prepare the way of the Lord, ache for a savior, need for a savior