Vedas have relavance in modern life, It's not only holiest mantras, they show us how to lead our life prudently.
It does not belong to any dharma. It's Sanathana Dharma Everlasting significance. We need to respect it wholeheartedly.The reason for this is as follows. the kAmo'kArshIt japam is done as an
atonement, a prAyaScittam for not having done the traditional
utsarjana sankalpa earlier in the year. The sankalpa for the japam says this
explicitly ('adhyAya-utsarjana-akaraNa'). Just as upAkarma is the
formal recommencement of Vedic studies, the utsarjana is a sankalpa done
to formally halt study of the Vedas and commence study of grammar,
prosody, pronounciation, astronomy, etymology, etc., as well as other
shastras, all of which are helpful in understanding the Vedas. The
year was therefore divided into two, one half for
studying the Vedas, the
other half for studying the VedAngas or Vedic accessories. The
utsarjana has unfortunately fallen into disuse for quite a while, so what
remains is the meagre prAyaScittam for not having done it. Therefore,
the important yajnopavItam changing is for the upAkarma.