We need to address two concerns here. First, what are the absolute truths God demands, and second, how does one deal with those who are sincerely convinced their beliefs are absolute?
To begin with, in the Christian faith there are four sources for discovering truth: scripture, tradition, experience, and reason. Of course, not all four are weighted equally and most Christians would at least give lip-service at giving scripture primacy. However, this isn't the case with every point of doctrine.
Many Christian beliefs are grounded tradition rather than in scripture. For instance, most Christians believe monogamy is the biblical model for marriage, but the Bible clearly supports polygamy except in the case of church leaders. The notion that polygamy is wrong is a matter of tradition (and in most Western nations a matter of law). Other doctrines grounded heavily in tradition include the trinity and the modes of baptism (immersion vs. sprinkling). Not that traditions are necessarily wrong, but traditions are beliefs and practices cherished by an individual or institution that may not be universally shared. But oftentimes people confuse traditions for absolute truth and they may defend them or promulgate them indiscriminately. The problem is that your traditional truth may not work for me.
Paul addressed this in his letter to the Corinthians. Apparently, some of the food available for sale in the markets was food that had been offering to other gods and buying and many thought that eating that food was immoral and against the natural laws of God. But Paul calls this tradition into question and says it is perfectly okay to eat meat that had been sacrificed to idols. He concludes by writing, "Why should my liberty be subject to the judgment of someone else's conscience?" (1 Corinthians 10.29)
But what of absolute truths from the scriptures? To answer that question we have to decide what the absolute truths are. In the beginning there was just one commandment - don't eat the fruit from one particular tree. We couldn't keep that one commandment, so we got ten. But that was too simple, so those ten were expanded to hundreds of commandments, prescriptions, and prohibitions. And that was too complicated, so Jesus (and others) reminded us that there are really only two commandments and every other commandment came from them: Love God supremely (Mark 12.30) and love your neighbor as yourself (Mark 12.31).
Now, some would argue these two commandments are simply behavioral guidelines, what really matters is "what you believe." Orthodoxy (right beliefs) has long been a concern of the Church and thousands of people have been excommunicated or put to death because they were "heretics," i.e., they didn't believe in some prescribed manner. However, the biblical writers seemed concerned about only a few points of beliefs, but were more concerned with right behaviors. The points of belief seem to be (1) God exists. This is, of course, the premise that makes everything else possible. (2) Jesus is the son of God. (3) Jesus died and overcame death. Nowhere in the Bible is there any other test of right belief, with the exception that right belief produces right behaviors (like doing whatever it takes to love God and to love our neighbors).
Everything a disciple of Jesus does (and believes) must be viewed through the filter of loving God and loving neighbor. And, according to the rabbis, everything else (in scripture) is just commentary.
So, how do you deal with those who try to force their non-essential beliefs on you (and/or your family)? Begin by setting some boundaries. If you prefer someone not speak of their beliefs to you or your family, say so. Be gentle and polite, but firm. No one should have to have their beliefs confronted if they choose not to. If these people don't respect your boundaries, remove yourself and your family from them. Jesus did not force himself on anyone, nor did his disciples, and nor should followers of Jesus today. Those who force their beliefs on others are not only misguided, they have clearly chosen to depart from following Jesus and his teachings. Stay away from them and choose instead to hang around those who are more concerned with loving people into the Kingdom of God than in arguing or intimidating them in.