It seemed to me that the Apostle Paul made allowances for circumstances that were very strong. For example, if I remember correctly, he brought up the laws the congregation should abide by in Acts 15:29 because people were going to murder eachother over the situation. In the congregation of Corinth there was a very shocking situation where I believe somebody was sleeping with his stepmom? But, even there the Apostle Paul wrote a follow up letter we see in 2nd Corinthians to not be to harsh in the words he tells them.
In other situations I have to wonder if there were strong situations going on and that was why he said some things that seem shocking to us today. It was a different time period and people were different then they are today. Notice he didn't give the same rules to all of the congregations....
I believe that is why it is so important to let love govern your conscience. It seems scriptures are taken out of context and verbatim to apply in our day to everyone and since the circumstances are very different it becomes a very unloving thing to do. For example, if the Apostle Paul only said not to eat blood specifically because he knew that people were going to murder others over the situation, that would be a very loving thing to do. To make that apply in our day with blood transfusions makes that a very unloving rule to make.