Is Jesus the only way to heaven?
Yep!
OK, I'm guessing you want a more detailed answer than that! (I don't blame you!) To better answer this question, we need to break it down into a few steps:
1. There was a dude named Jesus who lived 2000 years ago. Historians (even those who don't believe in God) will tell you that He is (or was) a real person - He's not a legend. Actually, there's more evidence for the existence of Jesus than for the existence of George Washington. You don't have to believe that Jesus is the Son of God, but it's foolish to believe that he never existed!
2. Jesus claimed to be the Son of God. Well, that's weird! Jesus said things like, "I give life like God the Father gives life," (John 5:21), "If you don't honor me, you don't honor God the Father" (John 5:23), and "The dead who hear my voice will live" (John 5:25) - just to name a few. The biggie came when Jesus called Himself "I AM" (John 8:58), the very name that God the Father called Himself in the Old Testament (Exodus 3:13-14). Needless to say, that didn't go over well! When the crowd heard Jesus say this, they tried to stone Him to death (John 8:58). Believe it or not - like it or not - Jesus claimed to be the Son of God, and it eventually got him killed.
3. Liar, Lunitic, or Lord? When someone claims to be God (like Jesus did time and time again), there are really only three possibilities. First, the dude is a liar. He knows he's not God, but he says he is anyway. Second, the dude is a lunitic. He's crazy! He believes that he's God, but he's not. Third, the dude is actually who he says he is - he's the Lord. There are no other possibilities. So, what do you believe about Jesus? Is he a liar, a lunatic, or the Lord? What does the evidence point to? For example, history records that 11 of Jesus' 12 disciples were killed because they claimed that Jesus is the Son of God. Would they willingly die for a liar? How about for a lunitic?
4. If "Lord," then what He says goes! If the evidence points to the belief that Jesus is who is says He is, the Son of God, then what He says is truth. After all, He's not just a guy - He's God!
5. Jesus claimed to be the only way to Heaven. Jesus clearly says, "I am the way and the truth and the life. No one come to the Father except through me" (John 14:6). It's not really about what that church says, or what the world says, or even what you say. It's about what Jesus says!
The good news is "For God so loved the world, that He gave His one and only Son, that whoever believes in Him shall not perish but have eternal life" (John 3:16). That eternal life is offered to the whole world - it's offered to me - it's offered to you! It's made possible by Jesus!