I think the biggest change in my life in the next five years will be change my job.
→ will be changing my job
→ will be that I change my job
will be 後面不能直接用動詞 change，要用一個名詞（動名詞、或是名詞片語）
I've been searching my passion for a long time
→ I've been searching for my passion for a long time