One of the most obvious characteristics of the Jews, is that they are always demanding a sign from those who speak to them about God (Deut. 6:22; Neh. 9:10; Jer. 32:20; Dan. 4:1-3; Mt. 12:38; Jn. 4:48; etc.). In fact, the Word actually states this in 1 Corinthians 1:22, which says, "For the Jews require a sign, and the Greeks seek after wisdom." The Jews demanded, and still demand, "credentials." That is why, during the first century Church, the Holy Spirit manifested signs; these signs were call the "signs of the Apostles" (2 Cor. 12:12). God sent the Apostles to go first to Jerusalem and Judea with the Gospel (Acts 1:8). And, for about twenty years, the Church was made up entirely of Jewish converts to Christ.
While no Bible student would question that the Apostle Peter was the primary messenger to the Jews, and the Apostle Paul was chosen to spread the Gospel to the Gentiles (Gal. 2:8), the Apostle Paul had the habit of going first to the synagogues of the cities with his message (Acts 13:5; 14:1; 17:1; 18:19; etc.). That is why God chose to work signs and wonders through him (Acts 14:8-10; 16:16-18; 20:9-12; etc.). By the end of the period recorded in the Book of Acts, God's focus was no longer on the salvation of the Jews, but was, and has been for the past 2000 years, focused upon winning the souls of the Gentiles.
Does that mean the signs, such as tongues, healing, and miracles has ceased? Most conservative evangelical Christians would say yes. However, I would ask two questions: 1) Is God still saving the souls of Jews (Rom. 1:16)? And 2), has the Body of Christ achieved Christ-likeness, to the point that the gifts of the Spirit are no longer useful (Eph. 4:11-16)? The answer to the first is a resounding yes; Jews for Christ is clear evidence of that! And note the word "also" in the text! The answer to the second is equally emphatic in that few, if any, would say the Church has arrived!
My testimony is that I was an atheist; God provided me with undeniable evidence that the Gospel is true, and the moment I trusted in Jesus Christ, I was indwelt by the Holy Spirit! No, I didn't speak in tongues, but I was a new creature! Praise be to God alone for my salvation!