“内在力量”常见的英文表达是 inner strength 。
例句：
She showed great inner strength in overcoming all those difficulties.（她在克服所有那些困难的过程中展现出了强大的内在力量。）
His inner strength helped him stay positive during the tough times.（在艰难时期，他的内在力量帮助他保持积极乐观。）