1-purity of intention means to work for the purpose of proximity to Almighty God and serving to people who are the servant of Allah Almighty
2- know that on the day of judgement, Allah Almighty will give people the reward of their works, and this reward is for the deeds which are done with pure intention and only for the sake of God.
Action follows intention; the more one's action is pure, the better and sooner it will be accepted. So, it is not advisable to do things for the purpose and intention of making others happy.
source : erfan.ir
