One of the complex things about Christianity is that it is about truth, but it is about love at the same time. If you try to focus exclusively on convincing people that the message of Christianity is true, they will be inclined to think that you are arrogant because, as Paul said in chapter 8 of his first letter to the Corinthians, “Knowledge makes people arrogant, but love builds people up.” If you want to build people up rather than alienate them, you have to ensure that any knowledge which you communicate is communicated in the context of love.
Paul goes on further to talk about the problem of eating food sacrificed to idols. We know that idols do not have any divine power, but others who have lesser knowledge might think that idols do have power, so it is best to abstain from eating food sacrificed to idols for the sake of such people. The knowledge that we have should not be used in an arrogant manner, but should be used to build people up in love.
The eating of food sacrificed to idols is not a burning issue today for most people, but there are plenty of other similar weaknesses to which Paul’s warning might apply, such as junk food, alcohol and gambling. We tend to think that a person should immediately be cured of all addictions and undesirable behaviours upon becoming a Christian, but sanctification is a process that is never fully completed in this life.