In each of these cases the standard is not the objective truth of scripture, it is the subjective truth of their feelings. In each case God's will is subject to the whims of man rather than the other way around. If you have ever tried to diet you know what it is like to be ruled by your appetite. Your intention is to eat sensibly and to cut out the junk food so you can maintain better health and be more productive in life. Your intentions are good until your stomach starts grumbling.
Many people start a diet right after a big meal and give it up as soon as they get hungry again.
The same is true in the spiritual life of many. They talk about obeying and loving the Lord but as soon as a strong desire for something sinful envelopes them they give in. Let me give you some examples of those who are governed by their passions, those who refrain from calling wrong behavior sin because they don't want to alienate anyone. We don't want to model our lives after a person who is governed by their appetite over the course of their life. The spiritual lives of these people have a tendency to swing one way or another depending on their feelings at any particular time.