"This 'knowledge' puffs up, but love builds up" (1 Corinthians 8:1).
Knowledge isn't everything.
We tend to equate knowledge with power. The more we know, the more we can achieve, and therefore the greater we can become. Ignorance is a curse that must be broken, a disease that must be eradicated. When we have understanding, we are superior to those who don't. We can be in charge because we possess a higher knowledge.
This mindset, so easy to fall into, goes directly against the core teachings of the Bible. Paul focuses on this in 1 Corinthians, where he warns that great knowledge is often a trap leading to disunity. He uses the example of eating food offered to idols. He and many of the Corinthian believers know that there is no harm in eating this food, as the god to whom it was offered is not real. But there are some new believers who come from an idol-worshiping background, and for them to eat this food is returning to their old beliefs. When they see another believer eating it, they're confused, and their faith is hindered.
In this case, superior knowledge proves to be harmful to someone else. In the case of the younger believer, this isn't so much an issue of knowledge as it is of the heart. He has believed in these gods for so long, and the ramifications of that are not going to go away in a day.
Our job as fellow Christians is to help those who are newer to faith than us to grow in their faith. We can't do that if we're flaunting our "superior knowledge," taking advantage of the freedom we have in Christ to do what others still consider to be wrong. True love for others means giving up our freedoms, choosing to not make use of the knowledge we have in favor of helping someone else grow.
As Paul points out, an increase of knowledge tends to make us arrogant. But if our goal is to love others no matter the cost to ourselves, then we are doing what pleases God. It's not what we know that shows our faith; it's what we do with what we know. And if what we do hurts others, then what kind of faith do we really have?