As Christians, we know that God is truth. We know that there is truth that is universal for all people, for all time, regardless of what anyone thinks. We know there is absolute truth.
So how does relativism fit into Christianity today? One word: denominationalism. There are literally THOUSANDS of Christian denominations in the world. Churches split and form new churches every day due to differences in Biblical interpretation. In the process, many are wounded and some never return to any church at all.
Not long ago, before I even considered Catholicism, I thought, "Why can’t we just agree on the essentials? Let's just agree to disagree and love each other." I even proposed this idea on a forum, which turned out to be horribly anti-Catholic. I was admonished by a moderator who said I was promoting relativism. He did not want this idea to be floating around while he was working so hard to get people out of the Catholic Church. Looking back, I see that while his motives were not exactly great, he was right not to want to promote relativism and it make me realize that I had accepted a bit of relativism myself on a small level. After all, I went to a church that believed what I agreed with... and I never questioned whether or not it was acceptable to believe differently from other Christians...
I asked myself, "Is it enough to just agree on the 'essentials'?" I soon realized that it is not enough. Not even close.
Can you imagine the three persons of the Trinity arguing about doctrinal differences or deciding what should be considered essential for Christians to believe and what shouldn't? Ludicrous!
There is nothing in the Bible that outlines what is and what is not essential. There are no primary and secondary doctrines. Instead, there is a very clear call to be in complete unity with one another and there is one truth:
1 Corinthians 1:10
I appeal to you, brothers, in the name of our Lord Jesus Christ, that all of you agree with one another so that there may be no divisions among you and that you may be perfectly united in mind and thought.
May the God who gives endurance and encouragement give you a spirit of unity among yourselves as you follow Christ Jesus...
(These are only two among MANY that speak of our call to be in unity with one another.)
But look at what has become of Christianity! Protestant denominations have been spreading relativism and diversity for 500 years, causing damage to the body of Christ. Don't like what one teaches? Start a new church and teach what YOU believe! The body of Christ was never meant to be so severed and split into different ways of thinking.
All things established by Christ are "essential" and they are not up for debate. We must accept all of God's word or none of it. We cannot pick and choose as if we are standing in a big cafeteria line of doctrines. This is one of the major things that caused me to seek truth... not relative truth found in denominationalism (by that, I include non-denominationalism, since it's a denomination of its own) that has SOME absolute truth.... but a complete, long-standing, historical, unified absolute truth. God is Truth and He told us that if we seek, we will find. There is only one truth within Christianity. ONE. As Christians, we must be diligent to seek it, find it, and tell others about it.
Christ established a Church to be the authority on all faith matters, not just an invisible church but a visible Church. This Church was established to be the pillar and foundation of truth (1 Tim 3:15) so we would know where to find it. So, how do we know which church? We go to the Church established by Christ himself... to the only Church that has been standing for 2000 years... to the Catholic Church!
As Catholics, we need to work to bring unity back to the entire body of Christ. We cannot let this doctrine of relativism continue to break us down. We have to continuously seek truth and put an end to the acceptance of the relativism that has divided Christians for the last 500 years.
There absolutely IS absolute truth and it can be known.
Jesus answered, "I am the way and the truth and the life. No one comes to the Father except through me.
You will seek me and find me when you seek me with all your heart.