That is why you have to keep writing your password. If you find the notifications annoying you can always turn them off and just check them whenever you want to.

If ur worried about someone else accessing your information you can set a passcode.
(means urll have to put in a passcode everytime you wake it from sleep)

Settings > General > Passcode Lock.

That way if you lose your phone or something. then it can be safe (ish)