"Then the dragon was enraged at the woman and went off to wage war against the rest of her offspring—those who keep God’s commands and hold fast their testimony about Jesus." Rev. 12:17
The Devil has been fighting the Church for almost 2,000 years. There have been times in history when it would appear that he had won. Times were dark, truth was slain in the streets. But always, the Church would bounce back. The Church has defeated every foe the devil has sent against it. He began by turning the Jews against the infant Church, but the Church only spread and grew. He tried to use the mighty Roman Empire to stamp out the Church, now the Roman Empire is a memory and the Church marches on. Down through the ages he has used various religions and governments to express his hatred for the Church and to try to destroy it. Even in our own day he marshes governments and religions to oppose the Church. They, too, in time, will go down in defeat.
Satan has three main ways he attacks the Church through his followers on earth. He is not very original, but he is effective for a season.
The first way the Devil attacks the Church is through persecution. I think this is his favorite way. He has an intense hatred of God and all who belong to God. This allows him to express his hate in a frontal assault. He kills, tortures and wounds in order to get people to deny the Lordship of Jesus Christ. He tries to force his will on them. By violence he tries to bend them to his way.
Satan infects his followers with this insane, illogical hatred of God's followers. Governments try to stamp our Christianity by throwing its followers into prison, torturing them, or murdering them. They are so blind that they cannot see that they are destroying those who are best suited for building their nation. True Christians are not a revolutionaries. They support those in authority [as long as they are not in conflict with the Bible]. They do works of mercy and help others inside and outside the faith. They are hard-working and build the prosperity of a nation. Any thinking government would want to have as many Christians as possible within its borders.
Nevertheless, government leaders, deceived by Satan, work toward their own destruction by attacking the Christian community. Not only is persecution merely blind, illogical rage, but also it is ineffective in the long run. Even back in AD 197, Church Father Tertullian observed that "the blood of the martyrs is the seed of the Church." Persecution actually causes the Church to grow! The more people see the reality of Christ in those who are willing to give their lives for Him, the more people are drawn to Christ. The light shines clear against the backdrop of darkness.
The second way the Devil attacks the church is through prosperity. Prosperity is a gift of God and comes as a result of practicing the principles of God's Word. However, when wealth increases it is easy to trust in wealth. Satan appeals to the flesh. We become more centered on comfort than on Christ. Enjoyment of life can become more important that sacrifice for the Kingdom of God. Our priorities shift. People who have not really been saved "join themselves to the church" because of the increased influence they might have or because it is the "in" thing to do. The church then becomes diluted with luke-warm people who influence its direction. Ultimately the Church becomes introverted and irrelevant in the world. This is probably more effective than persecution, but not as much "fun" from the Devil's perspective.
The third popular way the Devil attacks the Church is by inserting false doctines [teachings]. This is done in two ways. The first way is to send false teachers into the Church. These are people who are not Christians at all but teach lies under the guise of Truth. They deceive the unwary and untaught. Their messages are popular and appeal to the flesh. The second way is to deceive genuine Christians into believing and teaching false doctrines. He has been very effective when less than half the students graduating from Bible Schools/Colleges/Seminaries have a truly Christian world-view. A lot of genuine Christians don't even believe God told the truth in the first 10 chapters of Genesis!
In the West we have been infiltrated with false doctrine. Many Churches have abandoned solid Biblical exposition for popular motivational messages [which do have a place], because their members find "boring." Everything has to be "exciting" and "cutting-edge" or it isn't worthwhile. And so there is no defense against false doctrine with the personal and social destruction it brings. We are moving from a prosperity position to one of increasing persecution. Perhaps this is necessary to see real grow in the Church and in Christian maturity. On the other hand, perhaps genuine repentance and turning to God can restore true prosperity before there is a social collapse. Either way, the Church will win in the end. Through the blood of Jesus Christ the Church has never been defeated...and it never will.