Facebook has the option to disable Facebook but still use Messenger so you can conveniently exchange or text with others. All message content on Messenger is not lost but remains intact, completely different from permanently deleting your Facebook account. When you disable Facebook, there will only be Facebook personal pages created from the deleted account. Below are instructions for disabling Facebook and retaining Messenger.
Instructions for disabling Facebook and still using Messenger
Step 1:
At the Facebook interface, click 3 dashes icon below. Let's continue clicking cog icon to switch to the new interface.


Step 2:
Next, go to the interface as shown in your picture Click See more in Account Center. In the interface as shown, we click Personal Information section.


Step 3:
Let's keep clicking Account Ownership and Control section to exercise rights with Facebook account. In the next interface, the user clicks Select Disable or Delete to do so. This will display the Facebook personal page or Instagram account linked to Facebook that you want to disable.
Step 4:
After Select your Facebook account If you want to disable it, you will receive a warning that additional personal pages are also disabled. Enter password to disable Facebook.


Step 5:
Now you are asked Reasons to disable Facebook account is, select the cause and then click Continue below. Next Facebook will give you Choose the time to reactivate Facebook if you want.
Final Facebook will notify you that you still have the right to use Messenger as usual to text or make video or voice calls on Messenger. Press Deactivate my account to do it and you're done.