Why are electrons shared in covalent compounds

To obtain electronic stability, there is no other way to do it, or so I'm taught. They cannot 'give' electrons because they will not be electronically stable.

For example, chlorine gas, is composed of Cl2 molecules, covalently bonded, that is sharing their electrons. If one gave an electron to another, there would have been a choline 'atom' with 6 outermost electrons and another with 8, which is not electronically stable. By sharing, one shares an electron. As a result, both have 8 electrons in their outermost shell.

Hope you understood. Post if you need more.