Secularism is a synonym for Atheism.

Secularism is a belief system that is based on a fallacy of asserting a universal negative and a logical fallacy of an argument from ignorance. Asserting a universal negative is irrational unless you know the universal negative is true. You can only know it true by Divine revelation from Someone Who knows all things, Who cannot lie, and Who is qualified to say that something doesn't exist. Of course, that description is limited to Jesus Christ, Who is the Person that Secularism is all about denying. Arguments from ignorance are also fallacies.  Atheism depends on the twin dogmas of Naturalism and Materialism, both of which are also irrational beliefs based on universal negatives and arguments from ignorance.  Atheism is also dependent on Evolutionism, a fabrication about the history of the world that requires tolerance for a belief that conflicts with several known laws of science, ignoring a lot of the evidence, explaining much of the evidence with convoluted logic, and a dependence on the dogmas of Old Earthism and Uniformitarianism.  Uniformitarianism is based on a universal negative and an argument from ignorance plus ignoring much or the evidence or explaining it in a way that is irrational.  Old Earthism is a fabrication of the history of the Earth that must rule out the catastrophic Worldwide Flood of Noah's day of which the Bible speaks and which is so evident in geology.  Old Earthism is based on circular reasoning and wishful thinking. The Secularists are subject to a trilemma that only affects those who believe the unsupported assertion (another fallacy) that God cannot reveal Himself and His creation. This trilemma is most commonly known as the Münchhausen trilemma.

If Atheism were true, there would be no right, no wrong, no free will, no logic, no science, and no real love.  Atheism claims that all things are the result of randomness, so there is no reason to believe that are perceptions are even real.  If you take God out of the picture, you cannot know anything.

Atheists/Secularists claim that Atheism/Secularism is the default position. They claim that they don't have to defend their position because it is simply the neutral position. It is not the neutral position. It is a religion against God. It is ungodliness. Secularism/Atheism has used this argument to successfully allow their religion to become the State supported religion in most countries including the United States and Canada. And ungodly judges have enforced this government-preferred and supported religion. This has been going on so long that many Christian churches and whole denominations have become secularized.

While Atheism/Secularism/Humanism is based on a simple bold lie without any supporting evidence in the real world, Christianity is based on Jesus Christ, the Living Christ, Who reveals Himself to the Christian on an ongoing basis in the real world.  Believer's have the supernatural trust that is a gift from God.  By this trust, we see Jesus and hear His Voice.  It is Jesus Himself who reveals to us that the Bible is His Word, His Utterance.  And it is Jesus Himself Who speaks to us through His Word.   Jesus speaks to us through many different means: Scripture, intuition, bringing Scripture to our remembrance, apostles, prophets, etc.  When God speaks to us, faith comes and with faith comes a vision of hope.  This vision shows us who we are in Christ in an ever-more-clear understanding.  When God speaks, He instructs us what to think, what to say, and what to do.  Then, He does the work through us by His grace, His free gift of righteousness.  This righteousness of God in us is the moving of the Holy Spirit that transfigures us from glory to glory to be like Jesus, killing our fleshly nature and causing Christ to be more fully formed in us.  And this death to self, to the old adamic sin nature, and building up of Christ is the very thing that redeems us, sets us free from slavery to the fleshly nature, to Satan, to the pressures of the world, and to death. (some caveats about hearing God's Voice)