say to those with fearful hearts, "Be strong, do not fear; your God will come, he will come with vengeance; with divine retribution he will come to save you."
This is speaking to the remnant of oppressed Israel. Yet there are other senses in which this applies. Paul writes to the Christians oppressed by persecution, "God is just: He will pay back trouble to those who trouble you and give relief to you who are troubled, and to us as well. This will happen when the Lord Jesus is revealed from heaven in blazing fire with his powerful angels. He will punish those who do not know God and do not obey the gospel of our Lord Jesus. They will be punished with everlasting destruction and shut out from the presence of the Lord and from the majesty of his power." 2Thess 1:6-9 Part of the Christian life is to not fear the things of this life due to the hope we have, as Jesus said,
"And do not fear those who kill the body but cannot kill the soul. But rather fear Him who is able to destroy both soul and body in hell."
Matt 10:28 "Do not fear" is an encouragement, but it is also a command. Women especially, being the weaker vessel (1Pet 3:7), are subject to fears. But Peter writes that they will be behaving as Christians should "if you do what is right and do not give way to fear." 1Pet 3:6
God is our savior from the things of this world. But not only the outward oppression and injustices associated with the world of fallen man, but more importantly God is our savior from the sinful desires within, as Paul writes, "For I know that in me (that is, in my flesh) nothing good dwells" Rom 7:18a And observes "I have the desire to do what is good, but I cannot carry it out. For what I do is not the good I want to do; no, the evil I do not want to do— this I keep on doing." Rom 7:18b-19 But ends saying, "What a wretched man I am! Who will rescue me from this body of death? Thanks be to God— through Jesus Christ our Lord!" Rom 7:24,25
God poured out His divine retribution upon our sinful nature though the death of Jesus Christ and thereby justifying us and opening up heaven to all who would be forgiven through faith in His blood.
"And you, who once were alienated and enemies in your mind by wicked works, yet now He has reconciled in the body of His flesh through death, to present you holy, and blameless, and above reproach in His sight" Col 1:21,22