Dispensationalism is a way of looking at the Bible that understands God's unfolding plan––that He has worked in somewhat different ways with and through different peoples. The word "dispensation" comes from the idea “to dispense, that is, to measure out and appoint for.”
Especially, dispensationalism understands that in some ways God worked one way through Israel and another way through the Gentiles, and in some ways God worked one way through Israel and another way through the Church. This distinction between Israel and the Church is central to dispensationalism.
I'm a dispensationalist; I think it is the most faithful and honest way to understand some of the big themes in the Bible. However, I certainly don't agree with every idea that is proposed by dispensationalists or everything that goes under that name. There are a few things that are easy for dispensationalists to get wrong that we need to be on guard against. Here are some of the pitfalls.
It's true that Israel is not the Church and the Church is not Israel, yet there is still a wonderful continuity in the plan of God through the ages. Sometimes dispensationalists forget this, emphasizing the distinction so much that they miss what is common between the two and God's continuing thread of redemption woven into the fabric of history.
Different Salvation in Old and New
Some dispensationalists leave the impression that before Jesus, salvation was by works and after Jesus it is by grace through faith. It's good to remember that anyone who has ever been right with God has been, on the basis of grace, received by faith.
Separate Salvation for Jews Today
Dispensationalists rightly believe that God has a continuing role in His plan for Israel, the descendants of Abraham, Isaac and Jacob. But some take this truth much too far, believing that God has a separate path of salvation for the Jewish people. Often those in this error have been so zealous to encourage and bless the Jewish people that they forget salvation is only in Jesus Christ. This is true for both Jew and Gentile; Jesus will not rescue anyone who consciously rejects Him and His offer of salvation.
This Isn't Written for Me
Some dispensationalists are so zealous to divide between Israel and the Church that they think the teaching of Jesus in the Gospels was only or mostly for Israel, and not for the Church. Some try to explain that the Sermon on the Mount was for Israel, not the Church, so we don't have to be all that concerned with it. We must avoid this error.
Endless Dividing of Dispensations
The Scriptures tell us of a distinction between Israel and the Church; one easy example of this is Romans 11:25-26. Yet some also make definite distinctions in other eras of God's work. I've heard dogmatic teaching about the dispensation of innocence, the dispensation of conscience, the dispensation of human government, the dispensation of promise, and so on. There may be something to note about God's dealing with humanity during these periods, but in my opinion, because the Scriptures don't clearly make these distinctions, we should not dogmatically make them.
Every idea in theology can be misunderstood and badly applied. The same is true of the biblical distinction between Israel and the Church. By staying biblically grounded, we can avoid such errors and rightly divide His word of truth.