The chief biblical and historic distinctive of true churches is the Bible as the sole authority for faith and practice. The sole authority itself says that scripture is sufficient. By sufficient, the Bible is all you need. Another term for "all you need" is "sole." It is the only authority because it is all that you need. The idea that you need to concoct something new and different than what the Bible teaches contradicts sufficiency and sole authority.
The Bible is also practical. Practicality is practicing what the Bible says. You can practice it. You can fill up all your time doing what the Bible says. There is enough in there to do and to keep you busy just doing what the Bible says. There is enough time to do what the Bible says, not enough time to do what the Bible says and concoct something new and do it in addition to what it says. You've got to choose either the Bible or new things. Practicing what the Bible says will work. It's also what sanctifies us. We're not sanctified by our own opinions.
Very often a new strategy that is not in the Bible either changes the Bible or results in disobedience to the Bible. To start, it's not in the Bible. That really should be a problem, but very often, I notice, it isn't. People have no problem with something not being in the Bible. These same people will say the Bible is their sole authority. Where it isn't in the Bible, the Bible is not the authority for that -- that is you or someone else (or a demon). However, even besides the fact that it isn't in the Bible, which ought to be bad enough, new strategies not in the Bible undermine the Bible in many different ways. This post will not explain or describe how, but they do. People ought to be ashamed of themselves for thinking they need to supplement even the methods that scripture teaches.
In line with what I'm writing about, the Bible tells us all that we need to do about evangelism. It has in it everything that we need to know to fulfill God's will in evangelism. We don't need anything new for evangelism.
On a regular basis, I read new strategies or methods for evangelism. As a result of these new strategies and methods alone, churches have changed in nature toward the worse. Very often for what are perceived as short term gains, churches regress. Even when they seem to improve in the short term, it's not good, because God isn't receiving the glory for something men concocted.
Very often, when someone comes up with a new strategy or method, I've noticed, he thanks the Lord for it. Many say that God revealed it to them or gave the idea to them. Then they talk about how well it has worked, what success they have seen. I believe this is a form of continuationism, speaking about a new method as a new revelation from God. Often the explained or perceived success is tied to God having given it to them. The idea that God is revealing these new strategies or methods to them means that they have some kind of special unction or blessing with or from God.
If a new evangelism idea works, the inventor or "receiver" of the new method or strategy then might promote it in various ways, including at the conference. This new innovation will transform or improve your church. Your church will do better than before if you put the new idea into practice. "It's a good thing this man had this special connection to God to be given this great new idea that men had not yet received. It's obviously working because God gave it to him. You should get in on this working and see this success given by God." Other men covet the success, and so, eager to imitate it, they attend and then enact the method. More short term success begets even more short term success, validating the method. This is how these methods spread. "The new method is a key to success and you can have it too, if you use it."
What I've described in the previous paragraph has occurred again and again, now one generation after the next. There isn't less of this activity today. It's everywhere -- in evangelicalism, fundamentalism, and among independents. It will keep going if we do not repudiate it everywhere we see it.
Nothing is new in actual evangelism. Actual evangelism was settled with the completion of the New Testament. It has everything that we need.