Many issues in this fallen world present challenges in various capacities. This is not a simple question because what could be considered an “issue for Christianity” could be examined through the lenses of the Church, Christianity the religion, Christian orthodoxy (right thinking) and orthopraxy (right practice), or the Lord Jesus Christ Himself.
A question comes to mind that may shed some light on contemporary thinking. What will be our Lord? Will the Church—organization, institution or body of believers—be our lord? Will adherence to some perceived or human-created standards of right teaching and practice govern our every thought and action? Too many churches get bogged down and sidetracked with these things. Our one Lord is Jesus Christ Himself, whether we accept Him or not. Ephesians 4:1-6, "Therefore I, the prisoner of the Lord, implore you to walk in a manner worthy of the calling with which you have been called, with all humility and gentleness, with patience, showing tolerance for one another in love, being diligent to preserve the unity of the Spirit in the bond of peace. There is one body and one Spirit, just as also you were called in one hope of your calling; one Lord, one faith, one baptism, one God and Father of all who is over all and through all and in all."
The most significant issue facing the Church and affecting our thought and practice is whether or not we accept the Lordship of the God of the Bible. It is really going to be a question of whether or not people understand and accept the ultimate authority of Scripture. Too many people even now get at least distracted and at worst turn themselves and others completely away from the faith. Families are and will be neglected. Sin is accepted and propounded—and things are only going to get worse. “For the time will come when they will not endure sound doctrine; but wanting to have their ears tickled, they will accumulate for themselves teachers in accordance to their own desires” (2 Timothy 4:3). People—and whole churches—are already doing this, so over the next ten years we are going to witness things getting much worse, in the world and in the church. Judgement is coming. The question is will we be people who will endure God’s discipline and the world’s persecution? We can only do this by examining God’s Living Word and seeking deeper submission to the Holy Spirit.