This scripture is a golden chain of salvation, which consists of four links. One of them is a duty, "call them in advance", and the call is "a nova creatio". The first resurrection, the call is twofold:
(1) external call; (2) Inner call.
(1) External calling is God's grace to sinners, inviting them to accept Christ and his salvation. "In this way, the back is in front, the front is in front, and the back is in the back (there are scrolls here, because there are many people calling and few people choosing)" (Mt. 20 16). This call tells people what to do to be saved. If they don't obey, they can't be pushed.
(2) Inner call. When God offers grace and operates it in people's hearts, it is an inner call. God uses this call to renew people's hearts, and God effectively attracts people's will to embrace Christ. The external call makes people declare that they have Christ, but the internal call makes people belong to Christ.