Sincerity should be the watchword of a human being; it should run through his/her life and actions.
Equally true in the case of prayer. Sincere prayer is NOT lip labour. A sincere person’s prayer and actions will touch the heart of God.
Sincerity towards man will make you state your case and do what is required, unafraid, without equivocation. And you may be judged for it. And rebuffed, laughed at. Christ was. So He knows.
Towards God, sincerity will show when you condemn your sin plainly, without excuses, concealment or false pretences.
Sincerity will show at work, in ministry, when we don’t gloat over a skill or achievement that does not even exist.
Your family – especially children – will recognise it and learn from it.
Never wear masks or lie to self or others. You will have to keep defending your lies and covering up. Just do what you gotta do; and let it be for the glory of God and the wellness of man.