Can you eat on their behalf? Will their hunger be satiated when you eat on their behalf? No.

It is the same with prayer too. Each person has to pray for his/her own benefit.

If a priest is arranged for the Puja at home, then the benefit of that worship (punya, merit) goes to him alone. To add to it, he even gets the dakshina (money offered to the priest officiating the worship). Ultimately such Puja is nothing but a waste of money.

Agreed that you had to arrange for a priest to complete the Puja perfectly in your home. But then, what were you doing when the priest was conducting the Puja? Were you were sitting on the sofa, arguing with your husband and children or were you witnessing the Puja with faith and devotion?

Arguments are the outcome of idle time. When you keep yourselves busy at all times, you will obtain good wisdom and good strength. The lazy person, on the other hand, eats belly full food and then, having nothing meaningful to achieve, wastes time in useless activities.

(Q&A Session 27 March 2017)