There is an abundance of biblical evidence to support unconditional election. There is equal evidence to support the contention that God did not elect based on any merit on the part of the one elected.
Eph. 1:4 reveals that God chose His elect before the foundation of the world. Rom. 9:22-23 expands on this, "What if God, although willing to demonstrate His wrath and to make His power known, endured with much patience vessels of wrath prepared for destruction? And He did so that make known the riches of His glory upon vessels of mercy, which He prepared beforehand for glory." Nowhere does it teach that God chose based upon any future action of man. Indeed, Rom. 5:6 tell us, "For while we were still helpless, at the right time Christ died for the ungodly." Paul restates this two verses later in Rom. 5:8, "But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us." Peter approaches this from a different angle in 1 Peter 2:9, "For you are A CHOSEN RACE, A royal PRIESTHOOD, A HOLY NATION, A PEOPLE FOR GOD'S OWN POSSESSION, so that you may proclaim the excellencies of Him who has called you out of darkness into His marvelous light." Ungodly, sinners, darkness; there is nothing in man that merits salvation.
Ephesians 1 does not teach Unconditional Election, it says we were chosen "in him" which is conditioned on faith. No one is "in Christ" until they believe on Jesus in time.
Eph 1:4 According as he hath chosen us
in him before the foundation of the world, that we should be holy and without blame before him in love:
No one is "in Christ" until they believe on Jesus in time;
Rom 16:7 Salute Andronicus and Junia, my kinsmen, and my fellowprisoners, who are of note among the apostles,
who also were in Christ before me.
Paul said Adronicus nd Junia were "in Christ" before he was. This shows that a Christian is placed "in him" or "in Christ" in their lifetime when they actually believe on Jesus.
Then how could God choose us "in him" before the foundation of the world? FOREKNOWLEDGE. The scriptures say we are elect according to the foreknowledge of God the Father.
1 Pet 1:2 Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied.
God chose those persons he foresaw in his foreknowledge would believe on Jesus in time. God foresaw in his foreknowledge that Paul would believe on Jesus and chose and elected him upon this condition.
Those who do not believe on Jesus are not placed "in Christ" and therefore cannot be chosen "in him". Election is absolutely conditional, conditioned upon believing on Jesus.
Another verse that shows Christians were elected or chosen upon the condition of faith in Jesus is 2 Thessalonians 2:13;
2 Thes 2:13 But we are bound to give thanks alway to God for you, brethren beloved of the Lord,
because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth:
Yes, God chose Christians from "the beginning", but it was "through" both sanctification of the Spirit AND belief of the truth. Only those who believe the truth of the gospel were chosen.
This verse is not saying a person was chosen to believe, it is saying a Christian was chosen "through" belief of the truth.
Therefore, election is conditioned on believing the gospel of Jesus Christ. Men do this in time, but God in his foreknowledge could foresee who would believe and chose them.