The important thing is to make a difference in whatever large or small a way in your circles of influence, and to do so always with love while walking in the center of His will and being guided by him so that our work will have the greatest effect. We are not wise enough or powerful enough to figure out what work is the most important, what work makes the best of our talents, abilities, and capability given our spiritual maturity at the time, how to fit our work into the greater scheme of God's work for humanity, nor even how to best approach the work when we are led to a task by God. But Jesus promised in John 14:26 that we would have the guidance of the Holy Spirit to teach us “all things.” The Holy Spirit will guide us into what work needs to be done, and when He has led us to the work or to the person we are to serve or witness to, He will show us what to do and give us the words to say (Luke 12:12). Moreover, the Holy Spirit gives us the spiritual power for our spiritual work on God’s behalf (Acts 1:8). Additionally, we can do nothing without the power of God within us helping us, guiding us, and empowering us (John 15:4-6).
But every Christian has the Holy Spirit within them to help them. Some denominations teach that salvation and the indwelling of the Holy Spirit are separate events. But my understanding of scripture is that the Holy Spirit comes in at the moment of salvation. Romans 8:9 tells us that if we do not have the Spirit of Jesus (the Holy Spirit), then we do not belong to Jesus. I believe that Jesus enters our hearts at the moment that we ask Him to save us, and that He takes our sin upon Himself (2 Corinthians 5:21) and supernaturally applies His blood shed in sacrifice from the cross to our hearts to absolve us from sin (Romans 3:25) past, present, and future (Hebrews 10:14-16). Then, He leaves His Spirit within us as His seal of ownership and as a guarantee of our future inheritance (2 Corinthians 1:22) and for the purpose of the lifelong work of sanctification (Philippians 1:6).
Furthermore, as we grow over time through the work of the Holy Spirit within us, learning more how God views the world through His eyes of love, how His heart of love feels toward the people of the world, and even how God thinks – as we grow in character more and more like Him every day with His Spirit built up in us greater every day through His work of sanctification, then in time, we will hear His voice more clearly. Then, hearing His voice more clearly, we will respond more readily each time as our selfish will and desires shrink within us, and His will and character build up in their place.
Moreover, as we become more like Him each day, we will begin to respond instinctively in Agape love, simply knowing the heart of God and automatically knowing what needs to happen given the situation and knowing what would please God. Also, as we are more capable for the spiritual work God gives to us, God will use us more and more throughout the day. We will become more useful instruments in His Hand as we are molded to His Will and His Ways (Isaiah 64:8 and Jeremiah 18:1-7). As we become more useful, there will be days when we will be used by Him almost every moment of the day with small and large services to others: perhaps simply smiling at this lonely person we pass on the sidewalk, perhaps listening patiently and lovingly to this lonely elderly person who starts talking to us in the supermarket, perhaps letting someone out in traffic, perhaps even patiently bearing a slight from someone who is angry, frustrated, or hurting without responding in kind. There are so many ways God can use us and so many services that are needed in God’s work.
I pray that you will be attentive to and hear the guidance of the Holy Spirit in your life and that you will be blessed with opportunities not just to preach, teach, and witness, but always to model the wonderful love of our Amazing God by acts of service to your fellow man or woman.