“See the amazing love of God in making us His sons.
It is love in God to feed us, but even more to adopt us: ‘Behold what manner of love the Father hath bestowed upon us, that we should be called the sons of God!’ (1 John 3:1) It is full of wonder.
The wonder of God’s love in adopting us will appear the more if we consider this: that God should adopt us when He had a Son of His own.
Men adopt because they want children, and desire to have some to bear their name.
But that God should adopt us when He had a Son of His own, the Lord Jesus, here is the wonder of love.
Christ is called ‘God’s dear Son,’ (Col. 1:13); a Son more worthy than the angels, (Heb. 1:4), ‘being made so much better than the angels.’
Now, when God had a Son of His own, such a Son, here is the wonder of God’s love in adopting us:
We needed a Father, but He did not need sons.”
–Thomas Watson, A Body of Divinity Contained in Sermons Upon the Westminster Assembly’s Catechism (Carlisle, PA: Banner of Truth, 1692/1970), 234-235.