In spiritual things, it is the same. We can provide to atheists the finest, most logical, rational, and plausible arguments. In regards to rationality, all is flawlessly there. We can present a solid epistemological framework and use natural theology, through sound, logical inferences based on sound premises, on evidence and observation in the natural world, and correct inferences which lead logically to creation, and intelligent design, as the best, most case-adequate explanation of origins which top any kind of attempts to explain the issues in question by natural means.
Once, presented those arguments to atheists, in 99,9% of the cases, ( at least in my experience), once the dialogue has come to an end, the arguments exhausted, the response from the nonbelievers part is either silence or cheap excuses.
So reason alone is not the determinant factor that leads an unbeliever in God to become a believer. What is it then?
In the same sense, as everything has to be there, all life-essential chemical elements and biomolecules need to be there to kick-start life, life-giving "qualia" has to be injected, for life to start. So we read in Genesis 2.7,
Then the LORD God formed a man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being.
So it is with the unbeliever. Unless the lord breaths into him the holy spirit, he cannot become spiritually newborn and become a new creature in Christ. Being born again depends ESSENTIALLY from God. But there has to be a surrender, a predisposition from the unbeliever, an honest and true repentance to stop living autonomously to God. A will to re-start. To seek the Lord. Only THEN, a new believer can be born spiritually.
All the materialistic trash and evolutionary education have to be removed, which is a mere obstacle to find to Christ. And so all the invalid objections against the Bible. This is where we, apologists are in play. We can conduct an unbeliever from the dirty mud and pond of dirty intellectual waters and pseudo-philosophy, pseudoscience, and pseudo objections, to the clean spring and life-giving fountain. That fountain must contain the clean waters coming from God ( the word of God, God's holy spirit ). When the unbeliever drinks it, God does a miracle, and he can become spiritually alive. The blinkers fall off. He suddenly starts to see.
John 7:37-39 who believes in me may come and drink! For the Scriptures declare, ‘Rivers of living water will flow from his heart.’” (When he said “living water,” he was speaking of the Spirit, who would be given to everyone believing in him.
We are not demanded only to defend our faith with sound, rational, compelling apologetics. We need to be gracious, excel, and shine through our character, righteousness, honesty, and patience, but foremost, and in special, we need to pray and ask the lord as well to equip our words with the power of the holy spirit which reaches the hearts of unbelievers. It's those words that are like a hammer that breaks the rocklike, hardened heart in pieces, and transforms it into a heart of flesh.
Father, thank you for your Word, which endures forever. Lord, use us as your witnesses for those that dwell in darkness, don't know you, and do not believe. I want for your word to reach their heart like a spiritual fire, that wakes up their rock dead heart, and makes them become alive. Make their heart a fireplace for your Word and Spirit to burn with a passion to love you and a purpose to do start doing your will. Give us courage to share the truth with grace and boldness and with even more humility. I pray in the name of your Son, Jesus. Amen.