Paul did not want Christians to mishandle the Word of God. Some scholars think Paul did not want Christians to speak the wrong things about the Bible. Other scholars think Paul wanted Christians to teach people about the Bible so they can understand it.
Paul wrote about the gospel being veiled. This is a metaphor. Scholars think Paul was writing about people who rejected the gospel. If they understood it, then they would believe it. However, their sin caused them not to be able to understand true things about God. Satan does not want people to know true things about God.
Jesus had divine glory, just as God had when Moses saw him. When people came to Jesus, they realized that he was the “image”(εἰκών/g1504) of God. That is, Jesus showed people what God is like.
When Paul spoke about jars of clay, he used a metaphor. In ancient times, people often had clay jars in different sizes. They used them for many different purposes. Sometimes, people hid valuable things in them. However, they were inexpensive and easily broken. Paul wanted people to know that God would use people to tell other people about the gospel even though people were flawed.
Paul wrote that Christians always carry the death of Jesus in their body. This is a metaphor. Scholars think Paul wanted Christians to know they suffer in the same ways Jesus suffered. Other scholars think Paul was speaking about being persecuted for teaching people about Jesus.
Paul wrote that the things that caused him problems were momentary and light. This is a metaphor. That is, he thought serving God was greater than any problem. He also thought the promise to live together with God in heaven forever helped him when he was persecuted.
Paul wrote about the eternal weight of glory. This is a metaphor. Scholars think Paul was willing to suffer because he knew he would be with God in heaven one day.
Paul wrote about things that people could not see. Scholars think he was writing about things that happened in the spiritual world or in heaven. This is a place where angels and demons can be seen.