25so that there may be no division in the body, but that the members may have the same care for one another 26And if one member suffers, all the members suffer with it; if one member is honored, all the members rejoice with it. 27Now you are Christ's body, and individually members of it. 1 Corinthians 12:25-27
When one member suffers, the whole body suffers with that one individual. Why? Because we are all part of Christ's body. When we are engaged in being attacked by our common enemy we need the love, support and strength of those believers in our spiritual communities. The Christian life was never designed to be lived alone and certainly wasn't designed to engage battles alone. Here are two representative Scriptures that speak about battling spiritual wars together.
1 This letter is from James, a slave of God and of the Lord Jesus Christ. I am writing to the “twelve tribes”—Jewish believers scattered abroad. Greetings! 2 Dear brothers and sisters,a]" style="font-size: 0.75em; line-height: 0.5em; "> when troubles come your way, consider it an opportunity for great joy. 3 For you know that when your faith is tested, your endurance has a chance to grow. 4 So let it grow, for when your endurance is fully developed, you will be perfect and complete, needing nothing. James 1:1-4
As James discusses the reality and benefit of enduring troubles when they come your way, James is addressing the community, not individuals. When you read 'you' in the verses above, they are plural, not singular. The troubles that come your way are intended to be addressed in community so that the testing of your communal faith will produce a fully developed believer. It is not possible to be a mature believer apart from trials and troubles handled well with others by your side.
31 “Simon, Simon, Satan has asked to sift each of you like wheat. 32 But I have pleaded in prayer for you, Simon, that your faith should not fail. So when you have repented and turned to me again, strengthen your brothers.” Luke 22:31-32
In this passage from Luke, we read it and think, wait, this passage is about Simon Peter being sifted by Satan, not the community of believers being sifted. How is this spiritual war to be engaged by twelve apostles together when Jesus is speaking to Simon? Well, each of the 'you' phrases above are plural as well. It seems that Simon was representative of the whole and they were all going to be sifted in some manner for the purpose of strengthening them so in turn, they could strengthen their brothers.
War is hell and it must be fought in community. When we fight spiritual wars with others, we build a brotherhood that is strong and fully committed to one another. Just ask any athlete who has played on a team sport or a military person who has fought with a platoon of soldiers or with a short term mission team - each of them will tell you about the value of battling together for a common good. For believers, the common good is obedience to Christ. To be on mission together, fighting our common enemy and destroying his/their strongholds as we fight together.