If you do not want any other people read your text, or get access to your other apps, or mess up your phone settings, you'd better use an applock tool to protect your privacy.
IObit Applock can do that for you by locking Message and any other apps. If someone try to get access to it for three-times password wrong, IObit Applock will take the intruders photo and send to you. Watch this 50s-long video and try IObit Applock. https://www.youtube.com/watch?v=Gq-o757eOW8