Not every good thought, good idea or good intention has God's approval for you. David's good intention to build a house for the Lord; a permanent structure to house the ark sounded like a superb idea to Nathan. What could be wrong with such a honorable plan? Nothing, right? Wrong! God said, not so fast.
You see, not every good intention has God's consent. God's plans are so much bigger than ours any day. David wanted to build a house for the Lord. God wanted to build a dynasty for David - a never ending kingdom that would extend king David's line and put God's Son and David's descendant on the forever throne. An absolute incredible thought that only God could have conceived and only God could pull off.
I have had ideas and intentions that I thought were great until God slapped them down and knocked them out of the ball park with plans of His own making. We know that "A man’s heart plans his way, But the Lord directs his steps" (Proverbs 16:9 NKJV). Don't take your great idea to the next level until you have garnered God's decision on it. He may have others plans for greater things to come.