What is the necessity of ordinances and covenants? I posted about this recently but read this scripture and wanted to expand further.
20 Therefore, in the ordinances thereof, the power of godliness is manifest.
21 And without the ordinances thereof, and the authority of the priesthood, the power of godliness is not manifest unto men in the flesh;
That's exactly why, as Mormons, we are given the gift of ordinances. The opportunity to make commitment that build character that leads to godliness. It's not simply a life for testing how compliant we are, it's a life for becoming more like God. It's godliness not Godliness. The process of discovering the godliness within us. The inner god.
I consider the D&C to apply to me as a Mormon. But perhaps it's not something that has global, universal, application. Many other religions and philosophies have practices or principles where the "power of godliness is manifest." If this is the case, why would they need a baptism or an endowment which offers the same thing.
Mormonism is clearly a religion for people who need little to no ambiguity. The word of wisdom, for example, is designed for the weakest of the saints and has very little ambiguity. Where ambiguity exists it has either been further clarified ('hot drinks') or often ignored ('meat sparingly'). The whole question of tithing as gross/net is too ambiguous for some people and they clamour for a clarifying announcement. The instruction to wear garments when it was reasonable to do so was again too ambiguous so 'yard work' was added in (in UK the only yards are 'builders yards' - so I guess we can continue going topless when weeding our garden grown for food-storage).
D&C 19:6-7 is a favourite scripture of mine where God briefly lets down his 'absolutist' guard around us Mormons. "Yes, I know I said endless torment... It was just more express that way. It had the desired effect and so it was fit for purpose."
So yes, the priesthood ordinances are very much in place to help us discover the power of godliness in us. It works because in the performing the ordinance we are making and keeping covenants of sacrifice and service (to God and fellow-man). The ordinances are not some arbitrary card-carrying, tick-boxing exercise in obedience.
I embrace ambiguity. But also need to recognise and respect that I worship in a community of absolutes and need to be cautious to not undermine the absolutes of other people.