And when he then says that these “children of God” are “children of promise,” he means that they have their spiritual position not because of their physical connections, but because of God’s effective promise. The promise produced the position.

Listen to the prophet Isaiah 28:16. Therefore, this is what the Lord God says: “Behold, I am laying a stone in Zion, a tested stone, A precious cornerstone for the foundation, firmly placed. The one who believes in it will not be disturbed.

As it is written: “For Your sake we are killed all day long; We are accounted as sheep for the slaughter.” Yet in all these things we are more than conquerors through Him who loved us. 

God causes “everything” to work together for the good of those who love God and are called according to his purpose for them

For we know that all creation groans in unison with birthing pains up until now.  The difficult times of pain throughout the world are simply birth pangs.

For if your life is just about satisfying the impulses of your sinful nature, then prepare to die. But, if you have invited the Spirit to destroy these selfish desires, you will experience life. 

Rom 8:11 "But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you"

Therefore, since the mindset of the Spirit is the fruit and shape of the Spirit's life, the way God designed for us to walk and live is to have a spiritual mindset, not a fleshly one. From hostility to life to a spiritual mindset. And because we have this spiritual mindset, we walk that way – we live that way.We "do not walk according to the flesh but according to the Spirit."

The "law of sin and death" in verse 2 is the power and authority of sin which CONTROLS and rules in a life where God does not have the upper hand but where flesh is dominant. 

my new life tells me to do right, but the old nature that is still inside me loves to sin. Oh, what a terrible predicament I’m in! Who will free me from my slavery to this deadly lower nature? Thank God! It has been done by Jesus Christ our Lord. He has set me free.