For many years Christians have assumed that all the post rapture believers will need to do is repent and confess Jesus as their savior, and avoid taking the mark of the beast. But is going to the Temple to offer sacrifices the 3rd element and without it they are woefully without hope?
Once the Church is gone, the Bible’s focus shifts back to Israel for the final seven years of Daniel’s 70 weeks prophecy (Daniel 9:27). That’s why a Temple and animal sacrifices will be necessary again. For the rest of the world, I think life will be similar to Old Testament times when the twice daily Temple sacrifices for sin covered every believer no matter where they were, and Gentile converts made pilgrimages to Jerusalem as they could especially during the Spring and Fall Feasts.
But even this will only happen during the first 3 1/2 years. All Temple worship will cease during the Great Tribulation because the anti-Christ will have made it desolate, unfit for worship. Rev. 14:12 indicates that during this time the minimum requirements for maintaining one’s salvation will be to obey God’s Commandments and remain faithful to Jesus.