ssh -T git@github.com Permission denied (publickey)

ssh -T git@github.com Permission denied (publickey)

I tried to push my blog (Octopress) to github and got this error:
MacBook-Air:octopress bdeely$ git push origin source
Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
I generated an SSH key, saved it, and even linked it with my GitHub
account in the SSH key settings, but I went ahead and checked the status
and got the same error:
MacBook-Air:.ssh bdeely$ ssh -T git@github.com
Permission denied (publickey).
Does anyone know what is wrong and how I can fix this?