God is not only sovereign over all of creation, but He is sovereign in salvation as well. As the Scriptures say:
"For consider your calling, brothers and sisters, that there were not many wise according to the flesh, not many mighty, not many noble; but God has chosen the foolish things of the world to shame the wise, and God has chosen the weak things of the world to shame the things which are strong, and the insignificant things of the world and the despised God has chosen, the things that are not, so that He may nullify the things that are, so that no human may boast before God. But it is due to Him that you are in Christ Jesus, who became to us wisdom from God, and righteousness and sanctification, and redemption, so that, just as it is written: “Let the one who boasts, boast in the Lord,” (1 Corinthians 1:26-31).
"Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love He predestined us to adoption as sons and daughters through Jesus Christ to Himself, according to the good pleasure of His will, to the praise of the glory of His grace, with which He favored us in the Beloved. In Him we have redemption through His blood, the forgiveness of our wrongdoings, according to the riches of His grace which He lavished on us. In all wisdom and insight He made known to us the mystery of His will, according to His good pleasure which He set forth in Him, regarding His plan of the fullness of the times, to bring all things together in Christ, things in the heavens and things on the earth. In Him we also have obtained an inheritance, having been predestined according to the purpose of Him who works all things in accordance with the plan of His will," (Ephesians 1:3-11).
"And we know that God causes all things to work together for good to those who love God, to those who are called according to His purpose. For those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brothers and sisters; and these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified.What then shall we say to these things? If God is for us, who is against us? He who did not spare His own Son, but delivered Him over for us all, how will He not also with Him freely give us all things?" (Romans 8:28-32).
God's sovereignty in salvation is shown in that an individual can only be saved when God grants him the desire and ability to repent and believe in Jesus Christ:
"The Lord’s bond-servant must not be quarrelsome, but be kind to all, skillful in teaching, patient when wronged, with gentleness correcting those who are in opposition, if perhaps God may grant them repentance leading to the knowledge of the truth," (2 Timothy 2:24-25).