Torah is G‑d's wisdom. Intellect, by its very nature, allows for – and indeed demands – different avenues of understanding; how much more so when dealing with the infinite wisdom of the Infinite G‑d.
Our sages tell us that Torah can be interpreted in four different general ways: peshat, remez, drush and sod.
1) Peshat is the simple interpretation of the Torah. When the verse says (Genesis 1:1) that "In the beginning G‑d created the Heaven and Earth," it means exactly what it seems to mean, in a very literal sense.
Within these four methods of understanding Torah, there exist countless possible avenues of understanding2) Remez is the different hints and allusions which are contained within the Torah. One of the methodologies the Torah employs to make these hints is gematryia, the numerical value of the letters of the Hebrew alphabet. For example, the gematriya of "Bereshit bara" ("In the beginning He created)" is the same as "b'Rosh Hashanah nivra ha'olam" (on Rosh Hashanah the world was created)!"
Bereshit bara and b'Rosh Hashanah nivra are both 1116.
3) Drush (or Midrash) expounds upon the deeper meaning of the verse. The Hebrew word for "In the beginning" is bereshit. The midrash tells us that this word can be split into two words—b reshit. The Torah is telling us that the world was created for two ("b") "reshit"s ("firsts")—the Jews and the Torah. Although this is not the simple interpretation of the word, nevertheless it is a true and valid way of understanding the Torah.
4) Sod (secret) is the esoteric, mystical part of Torah. The Tikkunei Zohar (a book which gives seventy (!) different esoteric explanations for the word bereshit) explains that the word bereshit can also be split into "bara shis" (created [with] six). This is because the world was created through G‑d's six emotional powers: kindness, severity, beauty, victory, splendor and foundation.
Within these four methods of understanding Torah, there exist countless possible avenues of understanding. For example: There are many different ways to understand the Torah according to Peshat. That's why there are many Torah commentators who concentrate on Peshat -- Rashi, Ibn Ezra, Rashbam and many more – and they will very often (it seems, more often than not...) disagree on the literal meaning of a verse. In fact, according to Kabbalastic teachings there are 600,000 ways to understand Peshat, 600,000 ways to understand Remez, 600,000 ways to understand Drush, and 600,000 ways to understand Sod!
Any insight in Torah is acceptable as long as it (makes sense and) does not contradict any of our fundamental beliefs.
Our sages tell us that "any chiddush (novel idea) which a reputable disciple will ever come up with was already given to Moses by Sinai." Moses might not have heard this specific idea which the rabbi living thousands of years later has just thought of, but the basis of this idea was already given by Sinai.
G‑d gave us the tools to delve into the words of Torah and reveal the divine wisdom hidden therein.
When it comes to the halachah, however, there is only one truth. For whereas Torah is G‑d's wisdom which, as abovementioned, allows for different opinions, halachah is (not intellect, but rather) G‑d's will. And will is absolute, and does not allow for two ways to look at things.