The repercussions of some Gentiles, or non-Jews, becoming followers of Messiah sent shock waves through Israel and into other nations. Peter went to Jerusalem to give his testimony about how those Gentiles came to Christ without first converting to Judaism. The evidence Peter gave was that they had not only converted to Christ, but had been baptized in the Holy Spirit like the 120 disciples experienced on the Day of Pentecost. What was the evidence that proved they had been baptized in the Holy Spirit? They spoke in other tongues. This is a really interesting lesson.