Question

If a person were to approach, without preconceived notions, the “great sages of the generation” from the different streams (Haredi, Religious Zionist, Conservative, Reform, and within each group there are also sub-streams), and each one would present its worldview well grounded in sources (for example, you can go onto the Reform website and see that they back up their approach with various sources; you can see on Haredi sites unequivocal arguments from the sources that military enlistment is forbidden, and so on) — how is he actually supposed to decide which sector to belong to?