How did the first Kibbutzim manage to conciliate secular laicism with Jewish, religious, identity ( Shabbath, Torah, candles...)?

I have read a bit about the foundations of Kibbutz communities by Russian Jews influenced by socialist thinking and it is true that , when Marx wrote about religion as people's opiate, he thought about Protestant or Catholic Chrisrianity, but only becauseof they were the most immediate, daily, examples he could see. Marx, Engles and other thinkers never made, as far as I know, exceptions for Islam, or for Judaism

But the fiunder of the first Kibbutz were Jews wanting to preserve and streghten the Jewish identity, and such an identuty is above all religious

I know that in this socvial people are no longer used to think in absract manner and this post could be seen as akward, but I think that this question is important to understand the very first origins of Israel