You can use unflinching in expressions such as unflinching honesty and unflinching support to indicate that a good quality which someone has is strong and steady, and never weakens.
例句
...the armed forces, all of whom had pledged their unflinching support and loyalty to the government.武装力量一致保证坚决支持并效忠政府
英汉词典释义
adj.
<褒,尤文>坚定的,无所畏惧的
The ancient people who was successful, not only had exceptional talent but also had unflinching will.古人立大事者，不惟有超世之才，亦必有望忍不拔之志。