And 2 Peter 3:16-17 says very clearly that you are doing so at great peril.
Peter is talking about Paul's epistles here which contain our doctrine for this age of grace. Peter found it hard to understand how the Lord could go to the gentiles after he told them earlier not to. People were and still are twisting Paul's gospel and trying to tell people we are still under the law. Even Peter is saying here that the longsuffering of our Lord is salvation.