Question: As a Buddhist, when I attended a Christian funeral service, I noticed there was a lot of praise and thanks to god.
Answer: This is an attempt to remind Christians present of their faith in their god believed in, which also impresses upon non-Christians present of their faith. You can simply ignore this part as such a deity (with the attributes believed in) simply does not exist, as you can see at http://thedailyenlightenment.com/2017/02/all-too-human-the-league-of-gods It is puzzling why there should be grieving at such wakes if there is belief that the deceased is now with their god. There is also the question of why such a ‘loving’ god would ’cause’ a death that disturbs the survivors.
Q: I wanted to do silent Nianfo (practice of Amitabha Buddha’s name – ‘Amituofo’) but the deceased was very devoted to his religion. So I was concerned that should his consciousness, if still around, might be confused. Though we are of different religions, I hope he will have a good rebirth.
A: Yes, so as to be respectful and not disruptive at funerals of different faiths, silent Nianfo should be done, following silent words of guidance in your mind thought ‘aloud’ sincerely. You should have mentally went through the sequence of practice list at https://purelanders.com/2016/07/19/what-should-be-chanted-during-after-a-funeral , adapting where practical due to constraints, such as by visualisation instead of actual action.
The truth is, without doing the proposed above, the deceased, if still around, is likely to be MORE confused – because the god believed in does not exist, which means there will be no one definitely coming to guide him to a better realm, while he will be at a loss on what to do. This means the chances of having a good rebirth are lessened. If he does have a good rebirth, it will be based only on his good karma, which might not be enough.
Q: Not doing Nianfo, I listened to what was said during the service. I found myself going through an emotional ride and tears started to flow as people started to relate good deeds of the deceased. I try to control it but it was tough.
A: It was not a good idea to listen to the touching words because –  You would have wasted the opportunity to Nianfo, and  as you mentioned, it stirred your emotions till there was tearing, which is directly against the Second Great Essential taught by Great Master Yinguang: https://purelanders.com/2015/12/30/the-second-great-essential-%e7%ac%ac%e4%ba%8c%e5%a4%a7%e8%a6%81-pure-land-passport-section-3c
Such tearing along with the others can in turn stir much attachment in the deceased, thus disturbing his peace of mind, which endangers the quality of the last thought before rebirth, which might transpire at any moment. If you focus on sincere Nianfo only, there will be no extra ‘space’ in your mind at the same time to be emotionally disturbed. You should see yourself as offering the last sliver of true hope of spiritual rescue, among all present.
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