Why it is so, that contention has this effect of hindering spiritual exercises and comforts and hopes, and of destroying the sweet hope of that which is heavenly, we may learn from the doctrine we have considered. For heaven being a world of love, it follows that, when we have the least exercise of love, and the most of a contrary spirit, then we have the least of heaven, and are farthest from it in the frame of our mind. Then we have the least of the exercise of that wherein consists a conformity to heaven, and a preparation for it, and what tends to it; and so, necessarily, we must have least evidence of our title to heaven, and be farthest from the comfort which such evidence affords.
Jonathan Edwards, Heaven, a World of Love
Note that Edwards here is speaking about ungodly contention, not any and all contention. If that were the case, he wouldn't have published many of his own books, which contend for the faith against the errors of his day! Nevertheless, it is instructive to be reminded that our petty grievances not only steal away our earthly joy, but draw us away from that vision of heaven by which we are filled with hope for the peace of eternal joys, unfathomable. Contentment in all things may be the most difficult of Christian virtues to accomplish, as it requires the most discipline over the flesh and the most clear perception of the things that are yet to come.