It all boils down to spiritual regeneration, without it, the atheist/agnostic will continually spiral through systems compatible with their patterns of unbelief. In certain ways it is, but in other ways it's not so much of a mental or intellectual or rational problem, as it is a heart problem, there is a greater struggle of the will and desires, a struggle they cannot overcome in themselves, none of us can or could. The foolishness of preaching the Gospel of Christ is the power of God to salvation, it is foolishness to them who do not believe, but for those who believe, the power of God unto salvation. May the Lord give ears to hear and eyes to see.
"Amazing Grace! how sweet the sound
That saved a wretch like me
I once was lost, but now am found
Was blind but now I see"
- John Newton
"Newton wrote the words from personal experience. He grew up without any particular religious conviction, but his life's path was formed by a variety of twists and coincidences that were often put into motion by his recalcitrant insubordination. He was
pressed (conscripted) into service in the
Royal Navy, and after leaving the service, he became involved in the
Atlantic slave trade. In 1748, a violent storm battered his vessel off the coast of
County Donegal,
Ireland, so severely that he called out to God for mercy, a moment that marked
his spiritual conversion. He continued his slave trading career until 1754 or 1755, when he ended his seafaring altogether and began studying
Christian theology."
wikipedia