Помогите поставить шесть глаголов в правильную форму!

- Have you ever (thought) about the meaning of life?

- Of course I have! But the thing is that nobody (knows) the correct meaning of life. It (is) different for different people. The most important thing (is) to have a purpose in life. If you (have) a purpose in life, you (are/will be) happy. здесь оба варианта применимы