two: the cardinal number two, the count of a pair.
This is simply the number two, the word the New Testament uses whenever it counts a pair of anything: two brothers casting a net, two fish, two blind men, two coins, two thieves crucified beside Jesus. Across all of its occurrences it keeps this one plain sense. There is no hidden second meaning to hunt for, the way some small words carry a surprising range.
What does vary is the kind of phrase the number falls into, and a few of these phrases became fixed expressions worth knowing. One is distributive: pairing the word with itself ("two and two") to mean "two at a time," as when Jesus sends out the disciples two by two. Another is legal: "two or three witnesses," the standing rule from the law of Moses that no charge stands on a single voice, which the New Testament reuses for confronting wrongdoing and for weighing testimony.
None of these uses changes what the word means. In every case it is still the bare number two; only the sentence around it is doing the extra work. So a reader can take it at face value almost everywhere, while staying alert to the handful of set phrases that carry a particular force.