When you pass the exam for certification in ABC, which if any of these work, and which if any do not work?
You get a certification in ABC.
You earn a certification in ABC.
You obtain a certification in ABC.
When you pass the exam for certification in ABC, which if any of these work, and which if any do not work?
You get a certification in ABC.
You earn a certification in ABC.
You obtain a certification in ABC.
All of those, and also receive, "are given" and "are awarded". Without knowing anything else about the context, I'd lean towards "are awarded", as being more specific because it wouldn't apply to many other things you can receive/get/obtain/be given.
According to the COED, certification means
an official document attesting a fact, in particular:
• a document recording a person’s birth, marriage, or death: a birth certificate
• a document confirming that someone has reached a certain level of achievement in a course of study or training: a university-accredited certificate
• a document attesting ownership of an item or the fulfilment of legal requirements: a share certificate
The critical aspect of a certification (or a certificate) is to attest to a fact. That fact may be something that is ascribed or acquired, and if acquired, may be through the certification holders diligent efforts, or not.
You can certify that someone
There is obviously a wide range of affirmative efforts or accomplishments (or none) that may be the basis of receiving a certification. Consequently, while some certifications may have been earned, many are not. They are received, obtained, gotten, issued or any other term that means convey without indicating an accomlishment on the part of the holder.
There's no difference in meaning. In spoken AmE, get seems to be common. Obtain seems to be a better fit in formal settings. And earn doesn't seem to be that common at all. Earn implies that you deserve the certificate because you have worked very hard to get it.