Do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.
Now, the preceding verses point to the importance of Christian unity, and here we are made aware that our sins not only break our fellowship with our Christian brothers and sisters, but it even mars our relationship with God Himself
Now, just as a loving parent is grieved when his children go against his counsel, so is God grieved when we sin, for sin creates a ripple of stress in our relationships which begins to affect more and more people.
And because our call to be at peace with our fellow Christians is so delicately strong- delicate because of temptations all around us to sin; and strong, because only God can and will lead us through those temptations – the best place to find ourselves is continually learning how much God loves us, and how much we can really love Him.
Such is our safeguard against grieving our Lord as He continually prepares us for that day of redemption