Look at the Prophet's approach in this regard. One day he decided to advise 'Abdullah bin 'Umar to pray the night prayers.
He did not call him and say,"0 'Abdullah, pray the night prayer!" Rather, he advised him as if he was making a suggestion saying, "How nice is 'Abdullah! If only he were to pray the night prayers also!" In another narration he said,"0 'Abdullah, do not be like so-and-so. He used to pray at night, but then he left it."
In fact, if you are able to bring his mistake to his attention without him realising, then this is the best approach. A man sneezed in the company of 'Abdullah bin al-Mubarak but did not say:'al-Hamdulillah'. So 'Abdullah bin al-Mubarak said, "What does a person say when he sneezes?",
He said, "al-Hamdulillah,'
'Abdullah bin al-Mubarak said, "YarhamukAllah" (May Allah have mercy on you).
The Prophet Peace Be Upon Him had a similar approach. When he would conclude his 'Asr prayer, he would visit his wives one-by-one to sit and talk with them. Once he visited Zaynab bint Jahsh and found honey with her. The Prophet Peace Be Upon Him used to love honey and other sweets. He began to drink honey and talk to her, and ended up staying with her for longer than he would stay with anyone else.
Thereupon, 'A'ishah and Hafsah became jealous and planned that whoever of the two the Prophet visits should say, "I find that you smell of Maghafir!" Maghafir is a sweet drink, similar to honey but has an unpleasant smell. The Prophet Peace Be upon Him was always concerned that his body or mouth did not smell bad, as he used to speak with Jibril and the people. When he visited Hafsah she asked him what he had eaten.
He said, '" had some honey to drink when I visited Zaynab."
She said, "I find the smell of Maghafir on you!"
He said, "No. I only had some honey to drink. But I won't drink it, again."
He then went to 'A'ishah and she said the same to him. Days went by and Allah finally revealed the secret to the Prophet Peace Be upon Him, after a few days, the Prophet Peace Be upon Him informed Hafsah of a matter in confidence but she betrayed the confidentiality. He visited her one day whilst she had a guest known as ash-Shifa' bint 'Abdullah. She was a female Companion and a medical student who used to treat patients.
The Prophet Peace Be upon Him wanted to bring her attention to her mistake by approaching the issue indirectly, in order to be gentle with her. What did he do?
He said to ash-Shifa',"Wouldn't you teach her the 'incantation of the ants the way you taught her to write?"
The 'incantation of the ants' is what Arab women used to repeat, and everyone knew that it neither harms nor benefits.
The incantation as known amongst the women was composed of the following:
"The bride celebrates, dyes, applies kohl and does everything else, except that she does not disobey her husband"
The Prophet Peace Be upon Him wanted to indirectly to teach Hafsah a lesson by repeating," ...except that she does not disobey her husband:'
How beautiful is this approach towards correcting others' mistakes that leaves love intact in people's hearts, unshaken by errors and unpolluted by excessive offers of advice!
It is possible to drink honey without destroying the honeycomb. Do not advise a person as if he has disbelieved due to his actions! Rather, have good thoughts about him and assume that he made a mistake unintentionally, or without knowing.
"Even a good word is charity," Hadith.