Such a simple statement – in theory – but in practice…
Whatever you do, do it sincerely. ~Shaikh Husain Ash-Shadhili
Doing sincerely is never forcing. There is no compulsion – not with others, not with ourselves, even. While it is crucial that we understand why we do what we do, what motivates us and what our intentions are, we choose knowledge to coax ourselves into realization rather than pressure, ultimatums or demands.
Every action, every movement begins with a choice. It is the role of no one, not even a spiritual advisor, to force or impose.
When we choose to do something uncomplicated by motives or intent other than our love for Allah, His prophet (pbuh) and those who love Allah and His prophet (pbuh), that singularness-of-purpose results in genuine sincerity. Sincerity in action aligns us with success and is also known as good action or piety.
This is the gracious and honorable approach of Islam which Allah taught The Prophet Muhammad (pbuh) and it is the way of those who love and follow Him.