Telling the truth can be easy or very difficult depending on the situation. Mostly people lie in order to feel like they are much more intelligent or better than the person that they are having the conversation with. On average, we lie 3 times for every 10 minutes of conversation. Lying has become more and more often in common society due to the "get me famous " status that people want to achieve over Facebook or among their friends. However, this can be really embarrassing when caught in a lie and people will see you even more untrustworthy. Meaning maybe they will not talk to you about secretive stuff or something very sensitive in their life thinking that you are not a very trustworthy person.
Telling the truth is the most important factor when it comes to friendships or relationships in general. This is because telling the truth shows that you really care about the conversation and the person that you are talking to meaning that you will be able to help them grow in a much better way. "Nice Haircut" This is a sort of a white lie which is a lot less harmless to the people around you as its a opinion about how a person looks and not a concrete fact.
Telling the truth brings a lot of love inside of you from all the people around you. Using lies to control others its a very selfish act which can only be derived from the author of the lie feeling a lot of insecurity and fear. In order for real love and friendship to exist we must tell the truth to the people around us even though they might not like what they are going to hear. By not telling the truth you will put the relationship at risk and will decay rapidly overtime for both people as they feel that they can't trust each other.
Lies can be good or bad depending on how you use them. Lying can happen in one of those situations where telling the truth is not an option that they want to hear therefore lying to them could be a necessary good to do in order to maintain a stable relationship. However, if they find out that you are lying everything will literally go to shit.
So better off, don't lie. Always tell the truth and you will feel that you are a much better and happier person than you were yesterday.