Lets get the full context of Ephesians 2:8 by starting at the beginning of this letter to the saints at Epheus
Ephesians 1:7 In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace;
This relates back to Acts 2:38 and Romans 6
Ephesians 1:11In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will:
The above reference to the baptism in the name of Jesus Christ is where we have obtained an inheritance and it was according to the will of God his plan of salvation.
Ephesians 1:12 That we should be to the praise of his glory, who first trusted in Christ.
13 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
See when you trusted in the gospel which you obeyed in baptism see verse 7 you were sealed with that holy Spirit of promise,
Ephesians 2:1And you hath he quickened, who were dead in trespasses and sins;
2 Wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience:
3 Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
4 But God, who is rich in mercy, for his great love wherewith he loved us,
5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved

6 And hath raised us up together, and made us sit together in heavenly places in Christ Jesus:
See compare this with what he said in Romans 6 where he said this was when you were baptized into his death.
Ephesians 2:8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
9 Not of works, lest any man should boast.
10 For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.
Now see that the grace in verse 5 is what God worked in baptism in Acts 2:38/Romans 6:3ff Faith is not the gift salvation is the gift and it does not come from the works of the law as the Jews want to cling to but through THE Faith that was once delivered. For by od's workmanship in baptism as we see here and Romans 6 we were created in Christ Jesus go do good works of righteousness which God hath before ordained that we should walk in them.
Ephesians 2:11Wherefore remember, that ye being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands;
12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
13 But now in Christ Jesus ye who sometimes were far off are made nigh by the blood of Christ.
14 For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us;
15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain one new man, so making peace;
16 And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby:
17 And came and preached peace to you which were afar off, and to them that were nigh.
18 For through him we both have access by one Spirit unto the Father.
19 Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God;
20 And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;
21 In whom all the building fitly framed together groweth unto an holy temple in the Lord:
22 In whom ye also are builded together for an habitation of God through the Spirit.
These verse restate that it is in baptism that God has done this gracious deed of transformation.
So see I am not boasting but giving God the praise for the grace he has given me. So It does not help your case to just make stuff up take the word for what is says.
What did I make up does John 4:1 not say in black and whit in the KJV that Jesus baptized more even though he did not do the dipping but had his deciples to carry it out?
John 4:1 When therefore the Lord knew how the Pharisees had heard that Jesus made and baptized more disciples than John, 2 (Though Jesus himself baptized not, but his disciples,)
Again let me point you to Romans 6 where Paul tells us how we were born again the new birth transformed from dead in sin to alive in Christ. Paul said it was when we were baptized Acts 2:38 that we were baptized in his death (the cross the blood of Christ) it is clearly recorded in plain understandable words from God. Please read what the sriptures are telling you.
Yes and Paul told you in Romans 6 how God preformed this transforming work. It was through the baptism inJesus name that we were baptized with where we were baptized into his death (the cross the blood of Christ) in which GOD did HIS transforming work.