The sad narrative of our galaxy is that races seem inclined to commit genocide against other races on their home worlds. The Altarians and Drath once shared a home world. The Yor and Iconians once shared a home world. The Drengin and Korath once shared a home world. The Arnor and Dread Lords used to share a home world when they were known as the Precursors. Even the diplomatic humans shared a home world with the Neanderthals who were exterminated prior to the rise of modern human civilization.
But the Krynn are different. The Krynn home world started out with multiple sentient races. The Krynn, you see, are not a race but rather a people made up of many different sentient species. Tied together with a unifying culture, the Krynn (which loosely translates into "the way") believe they have unlocked the secrets to the universe and are on a holy mission to share these secrets with the universe.
The Jihad of Krynn is split between two technological branches. The first branch outlines the laws and order of the Krynn. These allow the construction of powerful centers for indoctrination which uniquely increase morale while spreading influence. The second branch spreads the way into the galaxy in extremely powerful influence modules for starbases.
What the Krynn may lack in technological sophistication they make up for in their ability to convert other species to their way. They can, after all, make the case that the Krynn have learned to share their world successfully for eons. With the galaxy full of evidence that other species, even the peaceful Altarians, ultimately fall into genocidal tendencies, the Krynn way of life has a growing appeal in a hostile galaxy.
The power of the Krynn lies in their ability to work together. This is best shown in their technological advantages in fleet combat where the whole is really greater than the sum of its parts. As the recent intelligence analysis from the Terran Alliance indicates, one could easily imagine a future where The Krynn dominate the galaxy without a shot fired.
The religion explained
The Way represents the ultimate direction for people to live their lives. The Krynn believe in a supreme being (what humans would call "God") who created the universe and then sent 4 guardians to safeguard the universe.
These guardians looked over the a massive crystal that the creator has put into the universe for the time when life would be added to the universe. The crystal would be used at a time when the universe was ready for life to exist. However, a 5th entity, a demon, came into the universe and attempted to corrupt the crystal. In doing so, the crystal was shattered and every tiny fragment of the crystal that came into contact with the right conditions began life across the universe.
The Krynn have put this belief to the test and have proven to their satisfaction the existence of what others call "dark energy". It is the invisible energy that the Precursors use. Their belief also predicted the existence of a "big bang" long before the science existed to provide rationale for that theory.
The Krynn believe that only through intensifying their sentience can they achieve salvation. Salvation, to the Krynn, means being able to exist as a sentient being of energy after the body has perished. The only way to intensify ones sentience is through converting others to The Way. The Krynn believe that all Krynn are connected and thus the more Krynn there are, the more intense the connections between them.
The existence of machinery that can harness the sentient energy of creatures (such as what the Drengin and Korath have) helps prove (according to the Krynn) that The Way ultimately requires no faith once one has full understanding.
Therefore, the Krynn must convert all sentient beings into being the Krynn even if it means bloodshed. The very afterlife of the Krynn is dependent on bringing the universe over to The Way. Even those who have long perished in body gain in sentience when new converts are added. Thus, the Krynn do not convert merely to save their own souls but to save the souls of all the Krynn who have ever lived.