When some professing Christians liken the Holy Spirit to a “funny and sneaky and silly blue genie” like the one in Aladdin, it becomes painfully obvious that many professing Christians don’t know the Holy Spirit, at least as they should. There are many things attributed to the Holy Spirit today, things like speaking gibberish, laughing uncontrollably, falling like a dead person on the ground or flailing around on the ground, and even so called “miracles” which never seem to be verifiable healings of significant and ongoing afflictions.
Many people are so yearning for the Holy Spirit to perform signs and wonders that they miss the subtle, but powerful ways the Holy Spirit serves and assures God’s people. After all, if signs and wonders are what most attract us to Christianity, we should carefully consider that when people wanted Jesus to perform a sign from heaven, “he sighed deeply in his spirit and said, ‘Why does this generation seek a sign’” (Mk. 8:12)? Jesus said, “An evil and adulterous generation seeks for a sign…” (Mt. 12:39). Could it be that lust for signs, wonders, and miracles blinds people to the more subtle, but equally powerful work of the Holy Spirit in God’s people?
Our comfort in life and death is inseparable from the work of the Holy Spirit in us. It is because we belong to Christ that the Holy Spirit dwells and works within us in powerful ways. One of the things the Holy Spirit does for our comfort is assure us of eternal life. Heidelberg Catechism 1 says that “by His Holy Spirit, [Jesus Christ our faithful Savior] also assures [us] of eternal life.” Besides sinners being rescued from their sin and given eternal life in Christ, sinners being assured they have eternal life is a supernatural work of the Spirit which gives them comfort, peace, and joy. The Apostle Paul wrote in Romans 8:15–17:
For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, “Abba! Father!” 16 The Spirit himself bears witness with our spirit that we are children of God, 17 and if children, then heirs—heirs of God and fellow heirs with Christ…
God gifted us with His Holy Spirit, the Spirit of adoption. It is by that Holy Spirit that we cry out with sincerity, “Abba! Father!” Our assurance of salvation comes from the Holy Spirit testifying along with our spirit that we are adopted children of God, even heirs of God and fellow heirs with Christ. When we struggle with uncertainty regarding belonging to Christ, the Spirit serves us by bearing witness to our adoption so we can feel secure.
But the Spirit serves us more. Heidelberg Catechism 1 adds that by His Holy Spirit Jesus Christ “makes [us] heartily willing and ready from now on to live for Him.” It is nothing less than the supernatural power of the Holy Spirit when sinners go from enjoying rebellion against God to enjoying obeying His law.
We can find comfort in life and death when we realize that we sincerely and excitedly want to obey God’s commands and strive to do so. This aspiration to live for God by obeying His law is something that only the Holy Spirit can put in you. The Apostle Paul encouraged Christians, “work out your own salvation with fear and trembling, for it is God who works in you, both to will and to work for his good pleasure” (Phil. 2:12-13). It is God, or we could say the Holy Spirit, who works in us to will to do and actually do God’s commands for God’s pleasure, never perfectly, but with increasing faithfulness and zeal.
Zacharias Ursinus said long ago,
assurance is obtained…secondly, from the effects of true faith, which we perceive to be in us; such as true repentance, and a firm purpose to believe God and obey all his commandments; for we are assured of having true faith when we have an earnest desire of obeying God; and by faith we are persuaded of the love of God and eternal salvation. 
Well said Dr. Ursinus. Let us find comfort in Christ as we repent, believe God, obey God, and trust in the love and eternal salvation of God.