He was transfigured before them

Mark 9:2
Now after six days Jesus took Peter, James, and John, and led them up on a high mountain apart by themselves; and He was transfigured before them.

The supernatural experience of the Transfiguration may be the high point for anyone who experienced it. A commentator said that God will never allow us to stay there - that is equally true. Such wonderful experience may be a good faith and confidence booster, but it does not directly benefit anyone else. God will give good things to His children, but He also wants His children to feed His sheep. So God may empower us from time to time, but we are to live mostly through the natural world, with all its flaws, and bring the Good News to others.

Fill up in my flesh what is lacking in the afflictions of Christ

Colossians 1:24
I now rejoice in my sufferings for you, and fill up in my flesh what is lacking in the afflictions of Christ, for the sake of His body, which is the church, 

Rejoicing in suffering is something unnatural for the normal or average person. The sound of someone rejoicing in their suffering brings confusion first, then perhaps a distaste. However, Paul has walked enough with God to know that suffering is not the important focus. Instead his goal was to empty himself and surrender to Messiah. Only then could he and can we live the way that God intended for us. It is in that state of surrender, then God will to mould us and use us for His Kingdom, which can mean to help others.

Woe is me if I do not preach the gospel!

1 Corinthians 9:16
For if I preach the gospel, I have nothing to boast of, for necessity is laid upon me; yes, woe is me if I do not preach the gospel!

Paul described his supernatural call by God to bring the Gospel to the world, first the Jews, then the gentiles. The call is an overwhelming force that Paul recognized and submits to it, in order for God to work powerfully through him. God chooses people according to His will, not based on people's merit or history. God will align circumstances to work out the calling and the mission. For the people, they still need to yield and surrender to God's will, so that God can make use of them.

whatever you have and give to the poor, and you will have treasure in heaven

Mark 10:21
1 Then Jesus, looking at him, loved him, and said to him, “One thing you lack: Go your way, sell whatever you have and give to the poor, and you will have treasure in heaven; and come, take up the cross, and follow Me.”

This passage about the rich young ruler is not about wealth. It is also not about holiness and sanctification, as the young man has lived an almost perfect moral life. Jesus saw that there was something holding the man back. He offered him a choice to make, there was still a chance he might change. However, the man admitted defeat and did not turn toward Jesus for help. Jesus wanted the man to come to Him, depend on Him and surrender to Him, He was not looking for perfection in the man. It mentioned that Jesus looked at the man and loved Him, He did not turn the young man away.

Lord, I will follow You wherever You go

Luke 9:57
Now it happened as they journeyed on the road, that someone said to Him, “Lord, I will follow You wherever You go.”

This particular man wanted to follow Jesus. However he had some personal matters to attend to, and it was to bury his father. In most circumstances, burying his father would take priority. In addition, given the obvious emotional state of the man after his recent lost, it would be understandable for the man to hold off his other duties and attend the mourning. This particular situation is deliberately recorded to emphasize there is nothing more important than Jesus Himself. When He calls us to follow, we must similarly leave all thing behind.

Remember that your brother has something against you

Matthew 5:23
Therefore if you bring your gift to the altar, and there remember that your brother has something against you.

God is quite serious with this command in Scriptures. The scene is of a person, presumably a committed believer, who comes to offer gifts to God at the altar. However, God's command is that this act of worship does not count much if there is still unforgiveness. The command is to simply stop before reaching the altar, when we remember that someone has something against us. Instead go and be reconcile with that person first, then return to the altar of God.

Give to him who asks you, and from him who wants to borrow from you do not turn away.

Matthew 5:41
And whoever compels you to go one mile, go with him two. 42 Give to him who asks you, and from him who wants to borrow from you do not turn away.

Our Lord Yshua demands few things from His disciples which seems very difficult to accomplish for us, based on our human nature. One such requirement is to be abundantly graceful and generous just like Himself. We can try very hard, but there may still be some resentment in our natural selves when we are too generous. It is only through God who can accomplish these things in us. Like all else, we simply need to surrender to Yshua and let Him work in us.