The disciples had nothing to gain by lying and starting a new religion. They faced hardship, ridicule, hostility, and martyr's deaths. In light of this, they could never have sustained such unwavering motivation if they knew what they were preaching was a lie. The disciples were not fools and Paul was a cool-headed intellectual of the first rank. There would have been several opportunities over three to four decades of ministry to reconsider and renounce a lie.