They chose to be single – Sh’mini
Nadav and Avihu brought esh zarah – strange fire – to the altar.
There are many views about the strange fire.
One is that they brought the wrong attitude to the sanctuary.
What was wrong with their attitude is also explained in many ways.
One suggestion is that they refused to marry – not that marriage simply did not happen but they made a conscious decision against it.
Maybe they thought marriage was not holy enough for them, too commonplace, not sufficiently spiritual. They thought too highly of themselves; they thought that if they had God they needed nothing human.
The reason why their attitude was criticised was that earthly ties and experiences are not to be belittled but regarded with great esteem and honour.
Marriage is the supreme example. Loving and respecting one another and sharing the privilege of building a home and – hopefully – rearing a family is the way two human beings experience the highest sanctity.
If they have God they try to bring His principles into their relationship.