Before the creation of the world, God has decided to save sinners to be made holy (Eph 1:4). This God fulfilled by causing them to be born again by the Holy Spirit (John 3:7-8) through His Word (1 Pet 1:23).
Salvation is accomplished by substituting the guilt of sinners with the righteousness of Christ (2 Cor 5:21), thereby declaring sinners justified (Rom 8:33).
The evidence of salvation is the continual transforming of our lives to the will and glory of God (2 Cor 3:18; Rom 12:2).
None can thwart God’s plan of salvation (Rom 8:38-39; Joh 10:27-30) and He will bring salvation to completion by glorifying the saved (Rom 8:29-30) to be with Him forever (1 Thess 4:17).
We are obliged to repent, believe in the Gospel of the Lord Jesus (Mark 1:14-15), put off sin, put on righteousness (Eph 4:22-24), and endure to the end (Matt 24:13).