5:9 Therefore we make it our aim, whether present or absent, to be well pleasing to Him. 10 For we must all appear before the judgment seat of Christ, that each one may receive the things done in the body, according to what he has done, whether good or bad. 11 Knowing, therefore, the terror of the Lord, we persuade men; but we are well known to God, and I also trust are well known in your consciences.
It is highly frustrating to encounter words in the Bible that miss the intent of what is really meant. It's usually easy to spot them because they generally don't fit. Rule number one when seeking to understand the Bible is that God's message to us and for us is good news. This passage as it reads in this English translation does not sound like good news at all. It sounds like we are all going to be dragged before God's judgement seat and get what we deserve, the good, bad, and ugly and God is a Holy Terror. It's a picture of God and our future that is or at least was not uncommon in Christian circles. There is a book written by a famous preacher called 'Sinners in the Hands of an Angry God'. The preacher was known for his ability to graphically portray the supposed eternal torments of hell. Contests were held in that era between preachers to see who could describe hell the best, with blood boiling in sinners veins etc...
However that picture of God doesn't reflect the general tone of Paul's writings. It certainly doesn't match what Jesus said: "If you have seen Me you have seen God". Can you picture Jesus roasting a person for eternity? Was He a terror?
So then what was Paul saying that got misrepresented and mistranslated by men with a warped view if God?
First the word is fear, not terror. It's the same word/meaning as when God said to Abraham "Now I know that you fear Me..." and the context (Genesis 22) was not of Abraham being terrified of God. In fact the Bible says later they were friends. The context is that Abraham had finally come to the place where He trusted God completely. Fear in the Biblical use of the word as it relates to our relationship with God is perfect trust. John wrote that there is no fear(terror) in love because fear (terror) has to do with torment and perfect love casts out all fear. It's impossible to have perfect love and be afraid of that person.
Paul was explaining that whether in this life or the next we live for Jesus. We live to please Him just as He lives for us. That's the very essence of love. And we will stand before God. Those who lived for themselves at the expense of others will get their reward as will those who like Jesus lived for others.
Then he tried to say "Knowing therefore what it is to trust God completely, we persuade men (to do the same) but we are well known by God (because we live by His constant leading) and I trust you can see that."
Paul all through this chapter and much of the last is describing from many angles the life of a Christian, a life of full surrender to the will of God, a life focused on the inward, not the outward, a life that looks forward rather than living in the moment, a life that is spent for others, not in taking from others, a life that would prefer to be Home rather than here but remains here to fulfill whatever mission God puts before them.
Paul knows what it is to fear God, to trust Him fully as Abraham did, and he is trusting his example will have an impact on the consciences of others, inspiring them to do the same.