Translation of "Testament" in Japanese

A testament to the incredible tenacity of the human spirit

これは人の魂が不屈であり

Before I die, in addition to my last will and testament, I want to write a love letter as well. No matter how shameful it may be, I don't have to be ashamed anymore.

死ぬ前には遺書のほかにラブレターも書きたい。どんな恥ずかしいこと書いてももう恥ずかしがらずに済むから。