The Revised Common Lectionary is shaped with deliberate intention, offering a selection from Hebrew Scripture each week, alongside a portion of the designated a gospel for the year (this year, Year B, it is Mark). For about half the year, there is no specific intention to correlate the Hebrew Scripture passage with the Gospel passage. In some seasons, however, there is a careful selection of the Hebrew Scripture passage, so that it resonates with and complements or intensifies themes in the Gospel passage.
This appears to be the case in the season of Epiphany, during Year B. Whilst the Gospel sections largely trace the opening scenes of Mark (1:1-3:6), the Hebrew Scripture sections are drawn from a range of Hebrew prophets: Isaiah, 1 Samuel, Jonah, Deuteronomy, Malachi, Hosea, and stories about Elisha in 2 Kings. (Not all of these passages, nor all of Mark 1:1-3:6, appear in Epiphany in 2021; in other years, when Easter is later in the year, the season of Epiphany stretches over more weeks, as the image below indicates.)
The selection of a prophetic passage alongside, and directly oriented towards, a Gospel passage, invites readers and hearers of these scripture passages to explore in creative ways what themes are highlighted. Back in Advent 2, Isaiah 40:1-11 was offered alongside Mark 1:1-8, the account of the activities of John the baptiser in the wilderness. The logic of this is clear; the Gospel actually directly quotes Isa 40:3 in Mark 1:2b-3, depicting John as “crying out in the wilderness: ‘Prepare the way of the Lord’.”

On the feast of the Baptism of Jesus, Hebrew Scripture passages underline the breaking open of the heavens for the voice of the Lord to be heard (Ps 29:3-9 and Gen 1:3; see Mark 1:11). The words of that heavenly voice are drawn from Psalm 2:7 (“you are my Son”) and Isaiah 42:1 (“with you I am well-pleased”).
In following weeks, there are clear resonances of theme between the two selections. On Epiphany 3 (24 January), both Jonah 3:1-10 and Mark 1:14-20 recount call stories. We read the story of Jonah, called to proclaim God’s message to the city of Nineveh, alongside the story of Andrew and Simon Peter, John and James, called to become followers of Jesus.
Jonah is effective in his proclamation to Nineveh, which in turn provokes God to change his mind about the calamity that he had promised for them. That is power!! But this was the second call that Jonah had received (3:1); the first had ended in quite a catastrophe (Jonah was thrown overboard and swallowed whole, 1:15-17).
Andrew and Peter, John and James undergo a period of learning-on-the-road with Jesus, before they start to proclaim with power. Theirs was a slowly-evolving call, requiring diligent attention and persistence. And other calls following this pattern are narrated by Mark—Levi (2:15), a crowd following him (8:34-36), and women in Galilee (15:40-41).

On Epiphany 4 (31 January), words attributed to Moses in Deut 18:15-20 are placed alongside Mark 1:21-28. These passages address the question: once we are called by God—then what?? Deut 18 contains a story about the promise God made to Israel, to “raise up a prophet”, while Mark 1 tells the story of the man possessed in the synagogue in Capernaum, who was exorcised by Jesus.
Both stories focus on the distinctive nature of faith in the particular contexts of these stories. The prophet of Israel stands over against “other gods” (Isa 40:20). Jesus of Nazareth is recognised as one who speaks “a new teaching—with authority” (Mark 1:27).

Both stories indicate that being faithful to the call will place us in challenging, daunting, perhaps even threatening situations. Faith is a call to trust in God as we enter into those situations. How is your call being challenged? How are you responding?
On Epiphany 5 (7 February), Isaiah 40:21-31 and Mark 1:29-39 offer stories at the start of a significant period of ministry; an unnamed prophet of Israel, speaking to the people as they prepare to step into the wilderness, journeying to the promised land; and Jesus, interacting with people soon after his own wilderness experience (Mark 1:12-13). Both passages are set at the start of a significant period of time; both stories reveal important things about the nature of God, and the ways that God engages with human beings in their lives.
God is portrayed as powerful and sovereign in Isaiah 40; that was comforting and reassuring for the journeying Israelites. God comes with power, also, in Jesus; yet in his humanity, Jesus needs time to replenish and rejuvenate (Mark 1:35).

His example tells us that we need to hold in balance the desire to do great things, with the need to care for ourselves and remain connected with God.
In other years, we would follow on to explore the interplay of passages in Mark 2 and 3 with excerpts from 2 Kings 5, Isaiah 43, Hosea 2, and Deuteronomy 5. But this year, Epiphany ends on 14 February, the last Sunday before Lent. On this day, the story of the Transfiguration of Jesus, in the presence of Moses and Elijah (Mark 9:2-9) is linked, quite understandably, with the account of Elijah ascending into heaven, after his mantle is passed on to Elisha (2 Kings 2:1-12).
This account contains the second of three occasions in Mark’s Gospel where we encounter the voice of God, affirming his Son, in the words, “This is my Son, the Beloved; listen to him!” (Mark 9:7; cf. Ps 2:7). The other instances are at the Baptism of Jesus (1:11) and at his Crucifixion (15:39, although this affirmation is placed on the lips of the centurion who was guarding him).
The three occurrences of this affirmation encompass the whole Markan narrative within this clear claim about Jesus—echoing the very title of this work: “The beginning of the good news of Jesus Christ, the Son of God “ (1:1).

of the Vanderbilt Divinity Library in the USA,
http://divinity.library.vanderbilt.edu/
See also https://johntsquires.com/2021/01/18/lets-get-down-to-business-beginning-the-story-of-jesus-mark-1/