"Unchanging heart" or "eternal heart" can be used to describe a heart that is always the same, regardless of the circumstances.
One possible source for this phrase is the Bible. In the New Testament, Jesus is referred to as the "eternal heart" or "unchanging heart" because he is the same yesterday, today, and forever (Hebrews 13:8).
Here are some example sentences using "unchanging heart" or "eternal heart":
Even though I've gone through a lot of changes in my pfe, my love for you has always remained constant, with an unchanging heart. (即使我的生活发生了很多变化，我对你的爱一直没有变，永远不变。)
I pray that I will always have an eternal heart, full of love and compassion for others. (我祈祷我永远有一颗充满爱和同情心的永恒之心。)
Despite the challenges he faced, he remained true to his principles and had an unchanging heart. (尽管他面临着挑战，他仍然忠于自己的原则，心态不变。)
One possible source for this phrase is the Bible. In the New Testament, Jesus is referred to as the "eternal heart" or "unchanging heart" because he is the same yesterday, today, and forever (Hebrews 13:8).
Here are some example sentences using "unchanging heart" or "eternal heart":
Even though I've gone through a lot of changes in my pfe, my love for you has always remained constant, with an unchanging heart. (即使我的生活发生了很多变化，我对你的爱一直没有变，永远不变。)
I pray that I will always have an eternal heart, full of love and compassion for others. (我祈祷我永远有一颗充满爱和同情心的永恒之心。)
Despite the challenges he faced, he remained true to his principles and had an unchanging heart. (尽管他面临着挑战，他仍然忠于自己的原则，心态不变。)