Gathered the church together (sunagagontes tēn ekklēsian). Second aorist active participle of sunagō. It “was the first missionary meeting in history” (Furneaux). It was not hard to get the church together when the news spread that Paul and Barnabas had returned. “The suitability of the Gospel to become the religion of the world had not before been put to the test” (Furneaux). Doubtless many “wise-acres” had predicted failure as they did for William Carey and for Adoniram Judson and Luther Rice.
Rehearsed (anēggellon). Imperfect active. It was a long story for they had many things to tell of God’s dealings “with them” (met' autōn) for God had been “with them” all the while as Jesus had said he would be (Mat 28:20, meth' hūmōn). Paul could recount some of the details given later in 2 Corinthians 11.
And how (kai hoti). Or “and that” in particular, as the upshot of it all.
He had opened a door of faith unto the Gentiles (ēnoixen tois ethnesin thuran pisteōs). Three times in Paul’s Epistles (1Co 16:9; 2Co 2:12; Col 4:3) he employed the metaphor of “door,” perhaps a reminiscence of the very language of Paul here. This work in Galatia gained a large place in Paul’s heart (Gal 4:14.). The Gentiles now, it was plain, could enter the kingdom of God (Act 14:22) through the door of faith, not by law or by circumcision or by heathen philosophy or mythology.