As written in the Book of the Word and other scriptures, Earth is home to the Thirteenth Tribe and it is assumed by members of the rag-tag, fugitive Fleet that Earth has ample defenses to take on the Cylon Empire.
Dynamite Entertainment comics
Artifacts purporting to lead to Earth are believed to be found in the libraries of Maytoria, prompting Commander Adama to authorize a mission to recover them before fleeing their homeworlds (Classic Battlestar Galactica Vol. 1).
After being struck by void lightning, Xam impresses his intense longing and desire for Earth into the minds of a swath of denizens in the Fleet, including Commander Adama, leading to visualizations of a false Earth (or an artifact) to be impressed in the minds of the Fleet's denizens (Classic Battlestar Galactica Vol. 2 #7-#11).
Maximum Press comics
Without the aid of the Seraphs, who give the Fleet a warping system known as the temporal overdrive in 7347, Earth is virtually unattainable in the Colonials's current generation—the journey would take thousands of yahrens. However, in 7362, Commander Apollo and Colonel Athena decide on one last, massive jump using the overdrive, which allows the Fleet to make it to Earth (War of Eden 1).