13For the promise that he would inherit the world did not come to Abraham or to his descendants through the law but through the righteousness of faith. 14If it is the adherents of the law who are to be the heirs, faith is null and the promise is void. 15For the law brings wrath; but where there is no law, neither is there violation.

16For this reason it depends on faith, in order that the promise may rest on grace and be guaranteed to all his descendants, not only to the adherents of the law but also to those who share the faith of Abraham (for he is the father of all of us, 17as it is written, “I have made you the father of many nations”) — the presence of the God in whom he believed, who gives life to the dead and calls into existence the things that do not exist. 18Hoping against hope, he believed that he would become “the father of many nations,” according to what was said, “So numerous shall your descendants be.” 19He did not weaken in faith when he considered his own body, which was already as good as dead (for he was about a hundred years old), or when he considered the barrenness of Sarah’s womb. 20No distrust made him waver concerning the promise of God, but he grew strong in his faith as he gave glory to God, 21being fully convinced that God was able to do what he had promised. 22Therefore his faith “was reckoned to him as righteousness.” 23Now the words, “it was reckoned to him,” were written not for his sake alone, 24but for ours also. It will be reckoned to us who believe in him who raised Jesus our Lord from the dead, 25who was handed over to death for our trespasses and was raised for our justification.

Summary
The Revised Common Lectionary retains the option of the more traditional Transfiguration reading for the Second Sunday of Lent, but the more recent practice of observing Transfiguration Sunday at the end of Epiphany recommends the Mark 8 reading.
Here, Peter has the unpleasant experience of being rebuked by Jesus for trying to persuade him away from his purpose of death. This even comes after Peter’s famous affirmation of Jesus as the Christ. The preacher should use this opportunity to remind the congregation of the necessity of the Cross, both in Jesus’ atonement for sin and also the believer’s life.
It is very easy to use this passage to affirm the necessity of Jesus’ death to accomplish the atonement for sin, but note that the image Jesus calls attention to is actually the carrying of the cross, which is the suffering along the way. This, Jesus says, is the vocation of every Christian.
The Cross is not an obstacle to get around, a bump in the road to a better life. The Cross is the road. What this means is that the believer ought to expect to suffer, but also to expect to suffer alongside Jesus, since he was the One who went ahead of us. Our sufferings in this life become a mysterious participation in Jesus’ suffering.
So the rebuke was for Peter’s own sake, since by diverting Jesus away from his suffering, Peter would have deprived himself of that supernatural solidarity that Christ offers to the sufferer. We risk the same when we seek our own comfort above all and avoid the hardships that can result from living the Christian life in a fallen world. In these moments, we must put our comforts behind us and walk the way of the cross with Christ, and so we will release the world and its pleasures and gain instead our souls restored by the deep and intimate connection that comes with Jesus the Suffering Servant.

https://www.preachingtoday.com/lectionary/

First Reading Genesis 17:1-7, 15-16

Psalm 22:23-31

23  You who fear the LORD, praise him! 
          All you offspring of Jacob, glorify him; 
          stand in awe of him, all you offspring of Israel! 
24  For he did not despise or abhor 
          the affliction of the afflicted; 
     he did not hide his face from me,  
          but heard when I cried to him.

25  From you comes my praise in the great congregation; 
          my vows I will pay before those who fear him. 
26  The poor shall eat and be satisfied; 
          those who seek him shall praise the LORD. 
          May your hearts live forever!

27  All the ends of the earth shall remember 
          and turn to the LORD; 
     and all the families of the nations 
          shall worship before him. 
28  For dominion belongs to the LORD, 
          and he rules over the nations.

29  To him, indeed, shall all who sleep in the earth bow down; 
          before him shall bow all who go down to the dust, 
          and I shall live for him. 
30  Posterity will serve him; 
          future generations will be told about the Lord, 
31  and proclaim his deliverance to a people yet unborn, 
          saying that he has done it.

Second Reading Romans 4:13-25

Gospel Mark 8:31-38