One of the metaphors that St. Paul uses about which we do not talk very much is Jesus as the new Adam. Over and over he repeats the pattern "if by one man...how much more..."
if, by the transgression of the one, death came to reign through that one, how much more will those who receive the abundance of grace and the gift of justification come to reign in life through the one Jesus Christ.
It is not just that Jesus undoes what Adam did, he undoes and surpasses it.
Of the list I chose the example above because it is the trickiest. After all, do we really think that being Christian means I am going to "come to reign in life"? The answer is no and yes.
If you mean by reign rule over others, then sorry–bad news,no.
If you mean by reign rule over yourself, then – good new, yes.
God's grace helps us not only to know the right thing to do, but to do it. True, there are a few things, like the startle response that we cannot control. But many many more that we can.
When we say, "She makes me so angry" or "They scare me."
No one can make you feel. The truth is he/she/they do something and you allow yourselves to be frightened our angry.
You cannot control the initial shock, surprise or startle, but you can control what happens next. Each of us with the help of God's grace can choose to allow the anger, fear, anxiety etc to overwhelm us, or with the grace of God we can reign over it. We can reign it in. We can allow the virtues of faith hope and love to be the reigning force in our life. We can choose to live.
St. Paul wants us to understand "how much more", how much greater God's grace is than any bad thing that might come our way.