Please tell me, if we have sent friend requests to people on Facebook that we had never met before and do not know that is like lying then what? Will we keep sinning by lying as long as we leave the friend requests stand to the persons we have sent to the friend request to on Facebook we do not know? Or will we have to go and personally remove each and everyone we have sent a request to if we seek to be forgiven?
In Facebook, "friends" are used in two different ways. It is a way to connect to people who are your friends and it is a way to become friends with people. By asking someone to become a friend on Facebook, you are simply inviting them to read what you post and read what they post and to be able to chat with them if they want. You don't have to know the person to ask them to be a Facebook friend. There is no sin involved. For it to be a lie, you would have to be deceiving a person into thinking you are a friend when you are not. But since the person has the choice of deciding whether to add you to his friends' list, there is no deception involved. If after a while the person doesn't wish to be a friend anymore, they can unfriend you.
However, you do need to use some wisdom and caution regarding who you invite into your "life" online. There are some not so nice people in the world and you might run into a few trying to randomly contact people. "The righteous should choose his friends carefully, for the way of the wicked leads them astray" (Proverbs 12:26).