"Complex" from the misconceptions about it, not what it actually is.
A widespread misunderstanding of the opponents of Dispensationalism is that they believe the key to Dispensationalism is not in the definition or recognition of a specific number of dispensations. Almost all theologians will recognize that God worked differently through the Law than He did through Grace. That is not to say that salvation was attained in a different manner, but that the responsibilities given to man by God were different during the period of the giving of the Law up to the cross, just as they were different for Adam and Eve.
The Jews were to show their true faith by doing what God had commanded, even though they couldn't keep the moral Law, for which reason they were given the sacrifices, imprinting in them the idea of blood shed for forgiveness, even though, as the writer of Hebrews said, the blood of animals did nothing for them. It would be the blood of Christ which provided the true deliverance God promised. When the apostle Paul said that as to the Law he was blameless, he didn't mean that he never sinned, but that he obeyed God by following the guidelines of the Law when he did sin, and animal sacrifices were offered for his sins by the priests in the temple.
Salvation came not by keeping the law, but by seeing it's true purpose in exposing sin and the great extent to which it exists in our lives. It forces us to turn to God for salvation, as we have no power in ourselves to seek Him. The Jews weren't saved based on how well they kept the law, as many of them thought. That would be salvation by works. They were saved through faith in God, and the work of Christ on the cross was counted for them, even though it hadn't happened yet. It is what was meant in Genesis 15:6 when God credited Abram's belief as righteousness, a righteousness that would come through Christ's sacrifice some 1,800 years later.
Dispensationalists will define three key dispensations, (1) The Mosaic Law, (2) The present age of Grace, and (3) the future Millennial Kingdom. Most will agree about the first two, and Covenant theology will disagree about the third, seeing this as the 'eternal state'. The reality is so-called Covenant Theology is much more fractured and divergent than anything of which those of us who believe in dispensational theology have been accused. Some convanentalists believe there is no literal Millennial Kingdom, but see a future literal fulfillment of the Davidic Kingdom. Others believe Israel has forfeited her promises from God given to Abram/Abraham. Still others accept a literal Millennial Kingdom, even a pre-tribulational rapture and the Second Coming of Christ at the end of the seven years of Tribulation.
A greater breakdown than that provides in the above paragraph, of specific dispensations, is possible, giving most traditional Dispensationalists seven recognizable dispensations.
- Innocence - Adam
- Conscience - After man sinned, up to the flood
- Government - After the flood, man allowed to eat meat, death penalty instituted
- Promise - Abraham up to Moses and the giving of the Law
- Law - Moses to the cross
- Grace - The cross to the Millennial Kingdom
- Millennial Kingdom - A 1000 year reign of Christ on earth centered in Jerusalem
While not everyone needs to agree on this breakdown, the point from the Dispensationalists view is that God is working with man in a progressive way. At each stage man has failed to be obedient to the responsibilities set forth by God. The method of salvation, justification by faith alone, never changes through the dispensations.
The responsibilities God gives to man does change however. The Jews were to be obedient to the Law if they wished God's blessing of Land. If they were disobedient, they would be scattered. However, God promises to always bring them back to the land promised to Abraham in the Abrahamic Covenant.
After the cross, believers no longer need the Law, though it is still in effect. It points to Christ as the one that took away sin through His perfect sacrifice.
We are under a new Law, the Law of Grace. We have more revelation about God, and are no longer required to keep ceremonial laws given to the Jews. The moral law is always in effect as a guide, but we are no longer condemned by it, since we have a savior that has overcome for us.
Now I ask you, is that complex, misrepresentative of truth? Hardly.