The people who does God's work has the habit of not declaring who they are working for. They leave it to ready and sensitive souls to recognize it.
Now compare that we Goldman Sachs CEO Blnakfein attitude and testimony before Congress. I am spoiled for choice which source to quote from but Business Insider was made convenient by Google.
Before you could even ask Khong Hee he would have told you he was doing God's work too. The Riadys of the Lippo group from Indonesia hung huge banners from newly acquired office towers praising God and that they just did the Lord's work.
I think best to let people decide. As a rule of thumb the noisier the more suspicious. I have serious doubts the American religious right are doing God's work which they shout from the bully pulpits they are, and what were the eight in ten who voted Trump thinking? I thought they got their moral priorities warped. On the other hand an over ninety year old nun wrote to me from Fremont months before the election about her fear about Trump becoming the next president. I told her not to worry but now on hindsight her insight was right. Now she is also the sort who quietly doing the Lord's work never try to tell you that she was.