Personally, sincerity is a virtue I hold in high esteem. We often blame people for many things without trying to understand the intention behind their actions. I strongly believe that when people make mistakes but are open about it and acknowledge their error, we ought to give them another chance.
Sincerity is the first step towards making amends. If someone does not admit they have done something wrong, they will never try to make adjustments. In the same way, when someone possesses the virtue of sincerity, we can always vouch for them. It means we know the things they can do and those that they cannot do. It also means that we know that even if they do something wrong, they'll be honest enough to admit it.
On several occasions, I have encountered people who lack this virtue and it was very disappointing. The most recent experience occured few days ago. I had organized an online training to teach photo and video editing. It was an advanced course so I attached a fee of #1,000 to it even though the knowledge I shared with them worths much more than that amount. Nevertheless, I love teaching so my passion was what kept me going.
About a week ago, a guy contacted me. He had seen the advertisement on a friend's status and was interested in learning. He registered for the training, however, he had an unusual request. He wanted me to create some AI photos for him for free while he would ensure at least eight people enroll for the training through him. I told him the photos are worth more than the #1,000 he paid for the training because I pay a weekly subscription on the app before I can generate photos. He promised heaven and earth to assure me that he'll keep his side of the bargain. I had my doubts but I decided it was a risk worth taking.
My brother, 
After about a week of advertising this training, few people registered. However, I saw several people who were genuinely interested but couldn't afford the fee so I added them to the training platform for free. I sent a reminder to the guy before the training but he refused to respond. Instead, he sent a message to his friend (on whose status he saw the ad) concerning the training without knowing I was aware. When I saw that he didn't reply my messages nor keep his word, I left him in the waiting room and added other people to the training platform for free. The friend contacted him on his promise and he responded rudely to her. I kept my cool and even though the payment was lesser, I decided to take it as if the #1,000 he paid was for the photos and not for the training.
I held the training last night and shared the testimonies of the participants to the waiting room to encourage those that didn't participate to also register for the final batch. The guy saw these messages last night and didn't contact me, obviously because of a guilty conscience. When he saw that I didn't add him to the group, he went ahead to send a message to the friend who referred him and requested that she should send him the training materials and teach him but she refused. He uploads on his Whatsapp status daily yet, till now, he never replied my message and I already stopped contacting him.
To me, this is the height of insincerity. He felt he was smart by what he did. If he had been sincere from the onset, I might have taught him for free just as I taught many other people for free. But because of his selfish desires, he told lies with the intention of deceiving me.
There are many people like this guy around the world. They lack sincerity and feel they can continually deceive anyone who comes across their path. In relationships, friendships, business and social interaction, sincerity is golden. The least he could have done was to notify me that he was unable to keep his side of the bargain, however, he never did that. Instead, he was trying to get access to what he didn't work for through deception and craftiness.
I have learnt the hard way that people are able to help only when you are sincere concerning your predicament. If people can be sincere in their words and actions, even while making mistakes, I don't find it difficult to forgive and overlook their errors.
Thank you for reading my article. What virtue do you hold in high esteem?