[Gehadu]

Konichiwa...
I've been trying to translate a few sentences and am relatively new to Japanese... (Still learning Hiragana and Katakana but getting there)...

How would i combine two sentences when the second sentence doesn't have a object but it uses the object from the first sentence?

The sentence that i am translating is the following:

Human Life gains luster and strength only when it is polished and tempered.
Thus, if i am correct, the sentence should look like this in japanese grammar:
Human-life luster and strength gain
-when polished and tempered.
Correct?

?