getting old

[Ashiuhto]

Please check the following sentences.

There is a big difference between getting old and growing up. Everybody will be getting old； however, not everybody will grow up.

[CarloSsS]

NOT A TEACHER

There is a big difference between getting old and growing up. Everybody will be getting old. However, not everybody will grow up.

The future continuous (will be getting old) refers to the process of getting old. My guess would be that what you wanted to express was the act of actually being old after some time. For that I would use future simple. As for the semi-colon, it does not work for me when it is used like that.