Hi Teddy,
I wasn't sure if your question was whether it was true that that's what JWs teach or if that interpretation is Biblically sound. It is true that JWs teach that only 144,000 should partake as they are the only ones going to heaven to rule with Christ--and this number partaking today should be decreasing with time, not increasing. But it is not Biblically sound.
It is based on stringing very distinct topics together. For one, the reference to little flock is only to his 12 disciples (or would it be 11 as they've somehow concluded that Judas had already left?) yet somehow they extrapolate based on nothing to get to the 144,000. The number is only mentioned twice in the entire Bible and both times in Revelation (ch. 7:4 and 14:1) and I find it interesting that those verses suggest they would be on earth NOT heaven. For instance, chapter 7 discusses the 144,000 being sealed before harm occurs to the earth and sea. Oh, the way they claim it's about those who will rule with Jesus is based on something the 144,000 don't even say (Revelation 5:8-10). And as freddo mentioned, the number is supposedly literal even though the reference over four verses to the distribution over the 12 tribes of Israel is purely symbolic.
What the Bible does say is that it's something to do in remembrance of Jesus (Luke 22:19-20; 1 Corinthians 11:23-26) and that those who don't take the bread and cup (eat his flesh and drink his blood) have no life in them (John 6:51-56). You should ask whoever is studying with you. I remember this was one of the issues that absolutely shocked me when I learned about it. You gather once a year to pass the symbols of Jesus's sacrifice for virtually no one to partake?? Exactly what is the point? And then there's logic: in the nearly 2,000 years since Christ died, there haven't been 144,000 faithful people? There's so much to this onion and the more you peel it, the more it stinks. But that's a start. Oh, and I've never been a JW so you can say this is apostate-free information
Also, all the verses that
Searcher specified are spot on. ANYONE who receives Jesus becomes a child of God.