"It is God’s will that we come to repentance and are saved. Whilst we are our own, we are given the choice to surrender to His will or harden our hearts. Once we have made that choice to surrender to Him as Lord, we are not given the choice again."
Paul was very particular about the traveling companions he had or allowed to be with him while he traveled. Remember the dispute he had with Barnabas concerning Mark? He expected those who went with him to be committed to Christ and serve Him with a whole heart. In multiple places he reminds the saints how he and those with him behaved in the cities they visited and ministered in and that they were an example of those who served Christ. There is a traveling companion of his named Demas:
Col. 4:14 NASB “Luke, the beloved physician, sends you his greetings, and also Demas
Phm. 1:23-24 NASB “Epaphras, my fellow prisoner in Christ Jesus, greets you, (24) as do Mark, Aristarchus, Demas
, Luke, my fellow workers
Yet the last we know of Demas is recorded in second Timothy:
2 Tim. 4:9-10 NASB “(9) Make every effort to come to me soon; (10) for Demas, having loved this present world, has deserted me
and gone to Thessalonica; Crescens has gone to Galatia, Titus to Dalmatia.”
Prior to this Paul considered Demas to be a “Fellow worker” but somehow Demas had now chosen to love this world instead. He made a choice after he had been bought by Christ to make the world his priority and he walked away from Christ.
In the Book of Revelation, chapters 2 and 3 are letters to the angels or overseers of the churches. In each of the letters the overseer is called by Christ to make a choice as to what the angel will determine as being his priority or what is preeminent to him. Every letter has this issue only concerning different circumstances. Every overseer is given the directive to "overcome." Being given the directive to overcome does not automatically mean that they will. Those who overcome will receive the reward mentioned (if they overcome). If they do not overcome they will not get the reward that those who overcome get. Many of those rewards are things we use to indicate salvation. What they chose to be preeminent determines whether they will remain in Christ or not.