Sincerity

As-Salaam `Alaykum. I have an intriguing question. I wonder: how could a Muslim attain sincerity concerning the actions he does both in private and public? How could I, as a Muslim, attain that?

Dear scholars, As-Salamu `alaykum. What does the word ikhlas mean? Jazakum Allah khayran.

Salam. I would like to ask:1- Is it permissable to "lie" or be ambiguous when you are trying to hide your good deeds because you do not want your intention to change and gain pride? e.g. if I want to do voluntary fasting, but I do not want my mum to know because I know my intention will change and i will feel pride. If she asks me if I had lunch i reply yes. Is that allowed, as I have problem trying to suppress pride.JazakAllah and may Allah bless you