Sincerity does not make something true. The contradiction is that you are using your definition and saying that "we're not to presume that we can speak for God." But that is precisely what you are doing by using your own definition.No I don't think they are contradictory. First off, the term I'm using is biblical. It's not as if I have never researched the term. I have extensively. And although it is mine, it is my most sincere in my perception.
The onus is on you to prove that your definition qualifies as blasphemy.If you don't think it is accurate, then you will be kind enough to show me where it does not qualify as blasphemy, in scripture, and correct me.
Thayer Definition:
1) to speak reproachfully, rail at, revile, calumniate, blaspheme
2) to be evil spoken of, reviled, railed at