The phrase "were earnest" can be replaced with several synonyms to convey different shades of meaning. For example, "were sincere" implies a genuine and honest intent, while "were zealous" suggests a passionate and enthusiastic approach. "Were diligent" emphasizes a focused and persistent effort, while "were ardent" connotes a fervor and ardor for a cause or belief. "Were earnest" can also be replaced with "were committed" to emphasize dedication and perseverance. Ultimately, the choice of synonym will depend on the specific context and intended tone of the communication.