In The Bible, 1 John chapter 3 verse 21, it says:
"If we don't feel guilty, we can come to God with bold confidence."
This seems to suggest that if our consciences are clear, then we can feel we are right before God.
In everyday life, though, it is not always that simple. Sometimes, if we really, really want something, we can ignore our conscience.
Sometimes, we have to make decisions when we don't know all the information. We might do wrong things, even if we follow our conscience.
Sometimes, people who genuinely are following their conscience disagree with each other. For example, a Christian soldier may believe they are doing the right thing, being in the army, whereas another Christian (for example a member of the Society of Friends) might believe that war, in any form is always wrong.