The following is an excerpt from The MacArthur New Testament Commentary on Romans 8.

And we know that God causes all things to work together for good to those who love God, to those who are called according to His purpose. (Romans 8:28)

For Christians, this verse contains perhaps the most glorious promise in Scripture. It is breathtaking in its magnitude, encompassing absolutely everything that pertains to a believer’s life.

And we know (8:28a)In the context of the truths that follow in Romans 8, these three simple words express the Christians absolute certainty of eternal security in the Holy Spirit. Paul is not expressing his personal intuitions or opinions but is setting forth the inerrant truth of God’s Word. It is not Paul the man, but Paul the apostle and channel of God’s revelation who continues to declare the truth he has received from the Holy Spirit. He therefore asserts with God’s own authority that, as believers in Jesus Christ, we know beyond all doubt that every aspect of our lives is in God’s hands and will be divinely used by the Lord not only to manifest His own glory but also to work out our own ultimate blessing.

The phrase we know here carries the meaning of can know. Tragically, many Christians throughout the history of the church, including many in our own day, refuse to believe that God guarantees the believer’s eternal security. Such denial is tied to the belief that salvation is a cooperative effort between men and God, and although God will not fail on His side, man might-thus the sense of insecurity Belief in salvation by a sovereign God alone, however, leads to the confidence that salvation is secure, because God, who alone is responsible, cannot fail. Beyond that theological consideration Paul is saying that the truth of eternal security is clearly revealed by God to us, so that all believers are able with certainty to know the comfort and hope of that reality if they simply take God at His word. God’s child need never fear being cast out of his heavenly Father’s house or fear losing his citizenship in His eternal kingdom of righteousness.

That God causes all things to work together for good (28:b) The extent of the believer’s security is as limitless as its certainty is absolute. As with every other element of the believer’s security, God is the Guarantor. It is He who causes everything in the believers life to eventuate in blessing.

Paul emphasizes that God Himself brings about the good that comes to His people. This magnificent promise does not operate through impersonal statements, but requires divine action to fulfill. God’s decree of security is actually carried out by the direct, personal, and gracious work of His divine Son and His Holy Spirit. “Hence, also, [Christ] is able to save forever those who draw near to God through Him, since He always lives to make intercession for them” (Heb. 7:25). And as Paul has just proclaimed, “The Spirit Himself intercedes for us with groanings too deep for words; and He who searches the hearts knows what the mind of the Spirit is, because He intercedes for the saints according to the will of God” (Rom. 8:26–27).

All things is utterly comprehensive, having no qualifications or limits. Neither this verse nor its context allows for restrictions or conditions. All things is inclusive in the fullest possible sense. Nothing existing or occurring in heaven or on earth “shall be able to separate us from the love of God, which is in Christ Jesus” (8:39).

Paul is not saying that God prevents His children from experiencing things that can harm them. He is rather attesting that the Lord takes all that He allows to happen to His beloved children, even the worst things, and turns those things ultimately into blessings.

No matter what our situation, our suffering, our persecution, our sinful failure, our pain, our lack of faith-in those things, as well as in all other things, our heavenly Father will work to produce our ultimate victory and blessing. The corollary of that truth is that nothing can ultimately work against us. Any temporary harm we suffer will be used by God for our benefit (see 2 Cor. 12:7–10). All things includes circumstances and events that are good and beneficial in themselves as well as those that are in themselves evil and harmful.