How do we know the Gospel is reliable?

In Colossians 1:23, Paul indicates that the Gospel has been preached to every creature under heaven, highlighting its broad and authentic reach. This universal declaration signifies its reliability as a message of salvation. Additionally, the Gospel's credibility rests upon the historical reality of Christ's sacrificial death and resurrection, which is central to its promise of reconciliation for sinners. Such an unwavering truth offers believers a solid foundation for their hope, assuring them of God's grace.