The yoke of bondage is an approach to justification and salvation, or righteousness, that relies on a syncretism of Jewish ritualistic legalism and pagan practices (usually rites of purification), while at the same time avoiding the sacrifice of Christ. This means that what we believe and who we believe in will determine whether we will be justified. Why is this approach a yoke of bondage? It cannot free a person from the penalty of sin or from Satan. It does not provide forgiveness. It will not put one into a position to receive God's Holy Spirit.
Paul is not writing to do away with the law! He is writing to clarify lawkeeping's relationship to justification and what a person believes through justification. If Paul were writing to do away with law, much of what he wrote later on in chapter 5 would not be there.
