When we say “a sincere prayer”, we are talking about that our prayer must be from the heart, because sometimes we meet people who want give to notice what they do and this is to boast before others.
Let’s see a definition of the word “sincerity”:
From the Latin sinceritas, sincerity is the way to express oneself without lies or pretense. The term is associated with truthfulness and simplicity. For example: “Sincerity is a value much appreciated in this company”, “The player once again showed his sincerity and acknowledged that he is playing below his level”, “Yes you would have spoken with sincerity, your partner would not have left you. “