Jesus tells Simon that Satan asked him if he could sift him like wheat. He tells him he prayed for him and that when he returns to strengthen your brethren.
Powerful! First of all this is a reminder that the devil wants to see how strong you are. He wants to push you to a state of failure. Jesus, after telling Simon about Satan, tells him but i prayed for you. Jesus is basically already claiming victory over Satan in this scripture. The statement, when you return, lets me know that you will come through it. Don't be discouraged because the devil is sifting you. Let him shake you up!
I love Snapple! On the bottle it tells you to shake it up. Most things that have been sitting for a while need to be shaken up. When things sit for a while, some of the good ingredients settle to the bottom. If God is going to get the best out of you, you need to be shaken up! Don't be upset when things are not going according to your plan. God wants all of you. In order for him to get the best out of you, some shaking must take place.
The last part- strengthen your brothers. When you have gone through something, it wasn't just to shake you up. It's also to help those who must also go through the sifting process. When God brings you through it, use your wisdom to strengthen others. You never know what someone is going through!