The Tyranny of Trying
"Paul is concerned that we not fall into false righteousness based on religious rules. He’s already discovered that to be a dead-end (see his own experience described in Phil. 3:6-9). The problem Paul is addressing here is that we might replace the reality with the shadow. We might commit ourselves to rites & rituals, rules & traditions, even strict regimes that involve self denial—all of which seem to make us holy—rather than energetically pursuing the true righteousness found in Christ alone.

He is also concerned that those who are holding to “hollow and deceptive philosophies which depend on human traditions and the elemental spiritual forces” are judging the people who are not (see Col. 2:16-19). In other words, in this church religious legalists are putting pressure on those who are not legalists to become legalists to prove their genuine commitment to Christ through legalism!"
Pastor David Lee