<p>4:5 <i>That He might redeem those that were under the law</i>- To return &quot;under the law&quot; therefore makes the Lord's work vain (2:21). The Lord's death was primarily to save Israel, those under the law. This was the focus of His work; it was their general rejection of it which made the more universal aspect of His death more public, as it were.</p><p><i>That we might receive the adoption of sons</i>- See on :4. Because He was human, of our nature, our representative, we can thereby be adopted as the sons of God- if we identify with Him. The proof this wonderful plan has been achieved is by the Spirit of adoption being sent forth into our hearts, whereby we are enabled to cry to God as 'Abba', 'daddy', just as God's only begotten Son did. The role of the Spirit is therefore crucial and cannot just be ignored or downplayed or manhandled to refer only to miraculous gifts in the first century. That is clearly not the reference here at all, for the Spirit is sent into our <i>hearts</i>.</p>