How do we know that God reveals spiritual truths to His people?

According to 1 Corinthians 2:10, 'But God has revealed them unto us by his Spirit.' This passage emphasizes that true understanding of spiritual matters is a divine revelation, granted not to all, but specifically to those whom God has predestined. God’s sovereignty in revealing these truths points to His grace—underlining the necessity of the Holy Spirit's work in illuminating the hearts and minds of believers. Without this divine intervention, the natural man remains in ignorance, unable to comprehend the spiritual truths that form the foundation of faith.