Before Jesus Christ established the Catholic Church, most followed their own delusions and worshipped created false "gods". These "gods" were, in essence, created and subject to change (both spiritually and physically). In a similar way, atheism and “secular humanism” are based off of subjective reasoning and have an unstable foundation which is subject to change (sensory data). With the one triune God, however, he is uncreated, not subject to change, and upholds all that exists within the universe.
Malachi 3
>For I am the Lord, and I change not: and you the sons of Jacob are not consumed.Hebrews 13
>Jesus Christ, yesterday, and to day; and the same for ever.James 1
>Every best gift, and every perfect gift, is from above, coming down from the Father of lights, with whom there is no change, nor shadow of alteration.Polytheism and atheism cannot offer this, but Catholicism can. It is for this reason, along with others, that many nations converted and baptized themselves into the Catholic Church.
https://www.youtube.com/watch?v=UvU8MGzmsLI 