The contemporaries of Jeremiah could not believe that God would actually allow his favored city, Jerusalem to be destroyed along with the Temple.  It happened.  The people of Judah had the Temple but it provided no hiding place when it came to God judging Judah for their unfaithfulness and evil ways.  Likewise, being "saved" does not exempt us from times of judgment.  Our doing must also match our being.  The Contemporary English Version of Luke 12:43 says:

Servants are fortunate if their master comes and finds them doing their job.

According to Micah 6:8 our job is:   ⁸ He has told you, O man, what is good; and what does the Lord require of you;  but to do justice, and to love kindness, and to walk humbly with your God?