You can deactivate your Facebook account temporarily and choose to come back whenever you want.
To deactivate your Facebook account:
1) Click the account menu at the top right of any Facebook page
2) Select Settings
3) Click Security in the left column
4) Choose Deactivate your account then follow the steps to confirm
If you deactivate your Facebook account your profile won’t be visible to other people on Facebook and people won’t be able to search for you, though some information, such as messages you sent to friends, may still be visible to others.
If you’d like to come back to Facebook anytime after you have deactivated your Facebook account, you can reactivate your account by logging in with your email and password. Your profile will be restored in its entirety (ex: friends, photos and interests). Remember that you will need to have access to the login email address for your account in order to reactivate it.
If you can not get into your Facebook account, you can reset your password.