Complex sentence: Watch Tower publications suggest that endurance in public preaching is the means by which Witnesses attain salvation, and that evangelizing frees them from the personal blood-guilt that would result if individuals died at Armageddon without having heard the message of God's kingdom.
Split into simpler sentences: Watch Tower publications suggest that endurance in public preaching is the means by which Witnesses attain salvation. Evangelizing frees them from the personal blood-guilt that would result if individuals died at Armageddon without having heard the message of God's kingdom.