For those of us who have trusted God for salvation, based on the finished work of Christ on the cross, God has already done for us the most difficult and costly thing He could ever do. He graciously sent His only Son to earth and then to the cross and the grave, in order to make forgiveness and eternal fellowship with us possible. We are now adopted children in His family, joint-heirs with His beloved Son, Jesus Christ (vv.16-17, 29, etc.) from whom we will never be separated (vv. 35-39), "whereby we cry, Abba, Father" (v. 15).
Consider our state when all this was being done for us. It is easy to love a beautiful baby that needs someone to care for it; but we were not at all attractive. We were filthy sinners, born in sin and habitually choosing to offend God's holy nature by succumbing to "the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath" (Ephesians 2:3). Furthermore, we were even "enemies" of the cross at the time "we were reconciled to God by the death of his Son" (Romans 5:10). Outside of His eyes of love and grace we would have appeared more like a repulsive maggot than a beautiful baby.
It stands to reason that He who has already done the most difficult, yea, infinitely difficult thing for us out of His great love, will continue to manifest that love to us, especially now that we are of His family. As our text tells us, He will "freely give us all things." With our best interests at heart, He will see that "all things work together for |our| good" (Romans 8:28).
"What shall we then say to these things? If God be for us, who can be against us?" (Romans 8:31). JDM