Perhaps because I was prisoner to it so thoroughly when I was young, I have an automatic recoil from whatever is the Spirit of the Age now. It is seldom the worst sin one can fall into - motives are always mixed - but I dislike it the most as it is the most common error, and the one that gets questioned least.
There are many Spirits of the Age, of course, including some within the church. To me it just seems obvious when people believe exactly what was popular at their seminary among people of the same gender and class that they should be immediately suspicious.
In discussing sin opposites, that immediately suggests that I am now too easily taken in by older ideas that have become unpopular. Hmm. I'm not sure that's true either. I have lists of things that have been popular in the church in my lifetime that are now mercifully gone, rather like the educational fads which come up every other year. I think it is better to say that I am likely to hang onto an idea that has been around in the church for centuries, on that basis alone. I must figure if it has lasted at all, there's likely something to it. That is not always so. Some errors and heresies have been around since the beginning, recurring every century to be pushed down again.