In 1990 in an Ensign article by Gordon B. Hinkley (First Presidency Message) he quotes Orson F. Whitney quoting Heber C. Kimball:
“I want to say to you, my brethren, the time is coming when we will be mixed up in these now peaceful valleys to that extent that it will be difficult to tell the face of a Saint from the face of an enemy to the people of God. Then, brethren, look out for the great sieve, for there will be a great sifting time, and many will fall; for I say unto you there is a test, a Test, a TEST coming, and who will be able to stand?” (Orson F. Whitney, Life of Heber C. Kimball, Salt Lake City: Bookcraft, 1945, p. 446.)
What is (or are) this (or these) test (tests), do you think?