Paul was speaking of the power of the new birth, not power for all believers to do apostolic sign gifts.The power was the ability to repent and serve God by the Spirit.;
Knowing, brethren beloved, your election of God.
5 For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance; as ye know what manner of men we were among you for your sake.
6 And ye became followers of us, and of the Lord, having received the word in much affliction, with joy of the Holy Ghost.
7 So that ye were ensamples to all that believe in Macedonia and Achaia.
8 For from you sounded out the word of the Lord not only in Macedonia and Achaia, but also in every place your faith to God-ward is spread abroad; so that we need not to speak any thing.
9 For they themselves shew of us what manner of entering in we had unto you, and how ye turned to God from idols to serve the living and true God;
10 And to wait for his Son from heaven, whom he raised from the dead, even Jesus, which delivered us from the wrath to come.
At birth we get the nature of God! At the Baptism we get power of the Holy Spirit! Now whether this happen all at once or seperate, that is something I am still searching out in scriptures!