H.H.Jayapataka Swami: Any service offered to the deity is a great mercy. And if you are doing direct service, it is especially serious matter. And even if you are doing backup service, it is also a good opportunity to develop your relationship. You can pray to the deity in the front that although you are not qualified, you are trying to serve the deity, and pray for Their mercy, and beg forgiveness for your knowing or unknowing offences, and then try to do your service with your full attention to all the details, thinking of the Lord all the time. Gandarvika Giridhari and Gauuuuranga! Hare Krsna!