We know that when a matter is mentioned as “one thing” it is the most important thing. No one would be careless to mention anything as “the one thing”.
The Bible says about one thing. One thing I have desired of the LORD, That will I seek: That I may dwell in the house of the LORD All the days of my life, To behold the beauty of the LORD, And to inquire in His temple. ( Psalm 27:4 NKJV) Here we read that the one thing, the most important matter is to desire to dwell in the Lord’s temple all days of our life. And while we are there, in God’s temple, to be able to contemplate and see the beauty of the Lord as well as enquire and find out matters, search and know God’s will in our live situations.