I think the issue was people who had been ROOTED in Christ, were now getting their spiritual roots in to other things...ie visions of angels, judiasm's legalism and such. People were making a BIGGER deal over their spiritual revelations and following of legalistic laws than in making a BIG deal over Jesus. Paul reminds them it's all about Jesus.
I think modern day parallel's could be undue focus on any aspect of our walk with God.
Undo focus on spiritual revelations and spiritual experiences at the expense of lifting up Jesus, the gospel, his word and spiritual transformation...
Undo focus on end times events, focusing on the minutia of how it's all going to come about at the expense of actually focusing on Jesus and becoming more Christ like...
Undo focus on playing the expose this guy game, instead of focusing on Jesus and becoming like Him.
Bottom line, any time there are roots in something other than Jesus, something has gone wrong. Anytime there is an undo focus on something other than Jesus and becoming like him, then something has gone wrong.