be in earnest

In Washington, Reagan Administration officials stressed that the Soviet leader's reform efforts seem to be in earnest, and avoided dashing hopes for better U.S.-Soviet ties.

From Time Magazine Archive

Those imams who still counsel against jihadist terrorism, says Kepel, may be in earnest.

From Time Magazine Archive

Surely—surely you can't be in earnest, sir—" "Oh yes, I am.

From The Hills of Refuge A Novel by Will N. (Will Nathaniel) Harben

Then as they heard the footsteps of the soldier they squatted before the fire, pretending to be in earnest conversation.

From The War Tiger Or, Adventures and Wonderful Fortunes of the Young Sea Chief and His Lad Chow: A Tale of the Conquest of China by William Dalton

Good!" exclaimed the drost: "there is, then, some meaning in it, and I now begin to be in earnest; for, hitherto, the whole affair has appeared to me somewhat like a joke.

From The Childhood of King Erik Menved An Historical Romance by Bernhard Severin Ingemann