Teen friends, Steve, Carrie, Cooper, and Gameboy embark on a weekend camping trip lead by their church youth group leader Stuart and his wife Beth. Joining them is an outsider Ashley, a self-involved rich kid, whose attitude causes a major commotion within the group, specifically between her and Carrie. Before it gets too out of hand though, Stuart takes this opportunity to share with the kids the incredibly powerful biblical story of Hosea; a story of immovable faith, impeccable commitment, and impervious love.

1970年的夏天，达斯汀，艾柏，马克三个12岁的少年有了一段永远无法忘怀的时光，他们认识了75岁的乔纳汉，一段忘年之交让三个调皮小男孩从此大不同！

这一年是1890年，圣经教授罗素-卡莱尔写了一份新的手稿，题为 "变化的时代"。他的同事诺里斯-安德森博士认为，卡莱尔所写的东西可能会极大地影响未来几代人的未来，于是安德森利用他的秘密时间机器，将卡莱尔送到100多年后的未来，让他看到他的信仰将导致什么。