It is easy to assume. We do it all the time in our personal and professional lives. Based on past experiences, we assume how the future will play out. Sometimes this is valid and sometimes it is not. Wisdom comes from discerning when to assume and when not to assume. This passage has assumptions in it that are logical assumptions, but still not right:
When the king was settled in his palace, and the Lord had given him rest from all his surrounding enemies, the king said to the prophet Nathan, “Look! I’m living in a cedar palace, but God’s chest is housed in a tent!” Nathan said to the king, “Go ahead and do whatever you are thinking, because the Lord is with you.” But that very night the Lord’s word came to Nathan: Go to my servant David and tell him: This is what the Lord says: You are not the one to build the temple for me to live in.
David and Nathan both assumed in this passage. David assumed that he ought to do something great for the Lord and Nathan assumed that David could do anything that sounded righteous, holy, and God-honoring because God had been with David through so much. The power of this story is not so much that the king and the prophet assumed something about God, but how they reacted when the Lord told them their assumptions were incorrect.
Nathan had to humble himself and go back to the king. He had to stand up in the king’s court and, in essence, say, “I know you depend upon me to deliver the word of the Lord to you, and you trust that what I say is from God. Unfortunately, I spoke out of turn yesterday when I told you to do whatever you want in the matter of building a temple for the Lord. The word of the Lord came to me and said that you may not undertake this project. No–you will not build a temple. I was wrong in saying you could do this and you were wrong in trying to do it.” David had to humble himself and accept the answer of no. True, he was given a promise by the Lord that God would build him a house, a dynasty, that would last forever, but the fact is that he is explicitly told not to build the temple.
Both of these men, the prophet and the king, humbly accept the rebuke from the Lord and admit they were wrong. This is the key in any relationship at all, whether it is our relationship with God or with other people. When we make mistakes, we need to be humble enough to admit them. When we assume, and those assumptions are not correct, we need to be confident enough to say we were wrong. In this way we will still follow after God, even in our mistaken assumptions, because we will show that we are willing to be reproved and corrected. To make assumptions is human, to admit when they are wrong is divine.