When we are doing sprint training for bobsled, it helps to run alongside someone who is slightly faster than we are in exercises known as Partner Interval Training. This causes you to push yourself harder to keep up and even beat them. Thus, you get faster when someone is there egging you on, even if just by running beside you. Coaches do this, trainers do this and good teammates do this. As athletes, we grow through such opposition. A lost race teaches us knew things. Heavier weights helps us grow faster and stronger. An injury helps us play smarter next time and teaches us to value our bodies and health even more. Even making a huge mistake in front of an even bigger crowd can be a learning experience if we let it.
What does all this have to do with the Devil? Well, every time he tempts us, and we resist, we grow stronger (hint: think of resistance exercises in the gym). When he tries to put doubts in our minds about God or life or our own worth, it gives us a chance to strengthen our faith or personal resolve or deepen our feelings of divine worth. When he distorts the truth, it provides an avenue in which we can dive into truth doctrine and "see things as they really are" (Jacob 4:13). When he laughs at our sins, it gives us the opportunity to feel the depth of the Savior's love for us and experience his cleansing forgiveness. When he smiles at our pains, we can grit our teeth and rise up and try again and find soothing comfort from Heaven's grace. For every obstacle the Devil puts in our way as we head towards the finish line, there is an opportunity to learn and grow and gain in wisdom and strength.
Opportunities that we would not have if he were not putting them in our path. Think about that. While he is trying so hard to make us suffer and slow us down as we head towards that Celestial finish line (and yes, he does succeed at times), the ironic thing is that the Devil is actually providing us with learning experiences that we would not have if he was not there to "run alongside us" as it were. His continual efforts to "win" and "score on our goal" keep us vigilant and focused (hopefully) and remind us of the importance of spiritual health and vigor.
So yes...I think when all is said and done and the hurts and struggles of this life are past, I AM going to shake the Devil's hand and say, "Thank you for providing the competition I needed to become my best and make it here to Heaven." It may sound crazy, but he is my brother after all and as evil as he may be, his opposition is propelling me forward towards my highest potential (as long as I choose to let it do so).