He who has a will is said be good, so far as he has a good will; because it is by our will that we employ whatever powers we may have. Hence a man is said to be good, not by his good understanding; but by his good will. Now the will relates to the end as to its proper object. Thus the saying, "we exist because God is good" has reference to the final cause.
Aquinas, Thomas. Summa Theologica
Any goodness in us is because of God who created us in His image. What does God look for in a person? Good will. That is a sign of His presence.
Many have an understanding of God that is flawed. Maybe all of us do to one degree or another. Yes, as I think about it, all of us have an inadequate view of God and His goodness.
Sometimes people think - and I include myself in this - that God is so good He will just overlook any fault and sin in their lives. No. His good will does not include condoning the things that will kill our souls.
Sometimes people think - and, again, I include myself - that God basically hates people for being such rotten sinners. Therefore He rains down judgment on us in the form of bad government, hurricanes, earthquakes, war, pestilence, and so forth. After all, we do not deserve His good will.
Yes, in a way that is true. We do not deserve nor can we earn God's good will for us. However, grace, mercy, and love are all motivating factors in God's good will towards us flawed and often sinful human beings.
Good will. Mercy. Love. Grace. That is what God moves us towards. Those are the goals and God graciously moves us towards those ends.
Think about God's extraordinary act of good will in sending His Son into the world. Remember the words of the angel.
There is some debate among Bible translators about how Luke 2:14 is to be rendered. Either way shows God's goodness as shown in the Incarnation. Remember. St. Thomas Aquinas said that the two fundamental truths are the Incarnation and the Divinity of the Trinity. All truth flows from those two sources.
Here is how the NABRE translates Luke 2:14 - with footnote.
Luke 2:14 New American Bible (Revised Edition) (NABRE)14 [a]“Glory to God in the highest and on earth peace to those on whom his favor rests.”Footnotes:New American Bible (Revised Edition) (NABRE)
- 2:14 On earth peace to those on whom his favor rests: the peace that results from the Christ event is for those whom God has favored with his grace. This reading is found in the oldest representatives of the Western and Alexandrian text traditions and is the preferred one; the Byzantine text tradition, on the other hand, reads: “on earth peace, good will toward men.” The peace of which Luke’s gospel speaks (Lk 2:14; 7:50; 8:48; 10:5–6; 19:38, 42; 24:36) is more than the absence of war of the pax Augusta; it also includes the security and well-being characteristic of peace in the Old Testament.
Here is the DRA's version, which is like the KJV´s.
Luke 2:14 Douay-Rheims 1899 American Edition (DRA)14 Glory to God in the highest; and on earth peace to men of good will.
How can a person be of good will? It all has to do with God's favor, which is another way of saying His grace. God's Spirit works in our spirits, giving us life, moving us towards what we were meant to be in the first place - people of good will as God is good. He moves us towards that goal, that end, that telos. It is all to His glory.