One thing that boggles my mind is that there are some denominations out there that genuinely teach that if you cannot speak in tongues, that proves you are not truly saved, because the Holy Spirit brings with Him the ability to speak in tongues. Is this true?
Now, it is true that speaking in tongues is actually Biblical. Regardless of where you stand on Cessationism, it is undeniable that the Bible does talk about some people speaking in tongues. However, this concept is easily abused. First, I want to point out the obvious: nowhere in the entire Bible does it say that one who cannot speak in tongues is not saved. The one and only criterion for salvation is faith in the Lord Jesus Christ. Near the end of John's first epistle, we read the following: "These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God." (1 John 5:13). The only question you need to ask, therefore, is do you know the Lord? If you believe in the name of the Son of God, it doesn't matter if you can speak in tongues or not, you have complete confidence that right now, you have eternal life, as surely as if you had already died and walked through Heaven's gates.
Conversely, it is actually possible to speak in tongues and not be saved. See, speaking in tongues is a very complex subject. In fact, being bilingual is, in effect, speaking in tongues. Can you speak two languages? Then you speak in tongues even without the direct aid of the Holy Spirit.
More importantly, the Bible actually tells us the purpose of speaking in tongues. It is not meaningless babble that no one can understand. Rather, in 1 Corinthians 14, Paul tells us that if no one knows what you're saying, you're speaking to the air (v9). Therefore, he tells us that he who speaks in a tongue speaks only to God. Thus, unless there is an interpreter, he who prophesies is greater than he who speaks in tongues. Go through the entire Bible, look for every time it mentions speaking in tongues, you will see that at no point is it mentioned as a requirement.
As a matter of fact, just two chapters earlier, Paul utterly rejects the idea that all must speak in tongues. In chapter 12, Paul speaks of the Church as a body. Every Christian has his or her place. The hand is not the foot. The nose is not the eye. He concludes this chapter by saying "Now you are the body of Christ, and members individually. And God has appointed these in the church: first apostles, second prophets, third teachers, after that miracles, then gifts of healings, helps, administrations, varieties of tongues. Are all apostles? Are all prophets? Are all teachers? Are all workers of miracles? Do all have gifts of healings? Do all speak with tongues? Do all interpret? But earnestly desire the best gifts. And yet I show you a more excellent way."
So what can we draw from this? Simple: The answer is no: not all Christians speak with tongues. If you cannot speak in tongues, well then fine, God just hasn't given that to you. He doesn't have to, you don't have to want it, and if He does ever see fit to give you such a gift, make absolutely sure you know how to use it to edify the Church. As for it being a requirement for salvation, woe betide the accursed fool who says it is, for he is preaching another gospel (Galatians 1:8). Pay them no mind.