Eternally Grateful: "Paul said he gave SOME this gift and SOME that gift as he wills."
Baptists misinterpret 12:31 to mean not every believer is intended to exercise these spiritual gifts, including tongues and prophecy. They misconstrue Paul's questions in 12:31 to imply that God never intends everyone to prophesy and speak in tongues. What Paul is really saying is this: "we observe that not everyone actually speaks in tongues or prophesies, leaving open the question of what God intends. Paul then makes it clear that at least the gifts of prophecy and tongues are meant for every believer. Thus, he goes on to teach, "You can ALL prophesy one at a time (14:31)." Similarly, when Paul says, "I want you ALL to speak in tongues (14:5)," he implies that this gift too is intended for everyone and then he encourages more of them to exercise this gift by saying, "I thank God that I speak in tongues more than all of you (14:18). This teaching echoes the pattern in Acts where initial reception of the Spirit is attested by speaking in tongues (2:4: 10:44-47; 19:6).
Eternally Grateful: "God does not need everyone to speak in an unknown language."
God needs nothing; we need the spiritual gifts, including tongues, a gift for every believer.
AustinC: "Let me rephrase: None of the persons whom God gave the gift of tongues were Christian before that event."
Wrong! The 120 disciples who were constantly at prayer (Acts 1:14-15), tarrying for the outpouring of the Spirit. Included in this prolonged prayer vigil were Jesus' mother and brothers, His female disciples, and the 12--all Christians. The Ephesian tongues speakers were "disciples" of Jesus (19:1). Cornelius was a god-fearer (not an idol-worshiping pagan) and he and his household in effect became Christians some time between sending messengers to bring Peter to explain more and hearing Peter's Gospel sermon. Remember, unlike Paul, Luke has no concept of the need for a regenerating work of the Spirit prior to the impartation of the gift of tongues.
Your error is the result of your failure to understand the sign significance of tongues for unbelievers in 1 Cor. 14:21-22 citing Isaiah 28:11-12). I will address that question in my next planned post.