What tenderness is implied here: It does not say, "Do not anger the Holy Spirit," but it speaks to us in the language of parents, "Do not grieve the Holy Spirit." It shows God's great grace to us that our sins and selfishness cause Him grief rather than wrath. Tyrants are not grieved at their subjects, they are angry and exact penalties for every infraction of their laws. It is FATHERS who are grieved at the waywardness of their children, their anger always being tempered by love. How God must love us that he could be grieved by our actions!
What motivation this is for godly living! I remember that in my childhood years I rarely feared my parents' wrath. Only on the rare occasion was my conduct guided by a fear of punishment. But there was one thing I dreaded: more than all else, I dreaded the look of disappointment and grief my disobedience would produce on the faces of my parents. Hence, I was a relatively obedient child, reigned in by the grief that only offended LOVE can produce. So with the believer and his God: it is not the fear of hell or loss that regularly guides him, but the dread of grieving the God Who loves him and Whom he loves.