And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption. (ESV)
In our culture we like to think that we are in charge. We call the shots. And that would make sense if we really were in charge. But Paul reminds us again that the Holy Spirit is dwelling within us. And as a result our decisions are to be guided by the Holy Spirit. We should never think that we are free agents, determining the best course of action and making decisions for ourselves. In fact, when we live lives apart from the guidance of the Holy Spirit, we are grieving Him.
Do you find it interesting that Paul speaks of God's Spirit being grieved? It lets us know that God has emotion. He can be grieved, saddened, disappointed. I can think back on many of the decisions that I have made in my life, disregarding the Holy Spirit's guidance within me, and assuredly bringing the Spirit of God grief upon grief.
The Holy Spirit is God at work within us. He is actively bringing about change in our hearts to enable us to choose the things that honor and glorify Him. When we continue to act out in rebellion to his wonderful work we grieve him. Paul reminds us that this Spirit has sealed us for the day of redemption. In other words, He guarantees our salvation. So, why would we work against him?
So, what will happen if we surrender our will to the will of God? What will happen if we allow the Holy Spirit to be in charge of our lives? Well, not only will the Holy Spirit not be grieved, but we will see genuine fruit. Paul talks in Galatians about the fruit of the Spirit.
 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness,  gentleness, self-control; against such things there is no law.  And those who belong to Christ Jesus have crucified the flesh with its passions and desires. (ESV)
Do you want to avoid grieving the Holy Spirit? Stop being led by your passions and desires. Ask the Holy Spirit to take charge of leading your life. If you do, you will begin to see some beautiful spiritual fruit in your life.