How does one know if the Spirit is speaking to them when it disagrees with another person who makes the same claim? Thus, the problem of Protestantism. This is the danger of listening to one's own "conscience", attempting to judge what the Spirit is saying - sometimes against the Church itself. A Body in dissension will fall, says Christ.
Regards
Prayer...diligent prayer. And as you said earlier (to paraphrase), if we focus on the big picture (Him), all our little disagreements melt away.
And if a disagreement still bothers us, reach out in humility instead of contentiousness and, at least in my experience, what we thought was a difference might be just a misunderstanding.