Well, there are two ways to heaven actually, and to do an exegesus of the scriptures does confirm this. The soul that sins dies. If you don’t sin, you don’t die, and will end up in heaven. This is from Moses, a prophet of old. Moses laid two choices, and there were only two. And, as they were laws, they are applicable to everyone. The law of blessings, and the law of curses. Sin, or transgress the law of God or the ten commandments, and you get the curses. Don’t sin, and you get the blessings. The only other way is if someone takes the place of your punishment, and you get the blessings while they get the curses. To say that there are many ways to God, and that Jesus’ death was only applicable to those who need to believe it, doesn’t really make sense with either the old testament, nor the new testament. So yes, Jesus is the only way to heaven, since all have sinned.
What about those who’ve never heard about Jesus is a common question then, and the Bible is clear that those who’ve never heard the law, are judged as not having the law, although their conscience will bear witness that they’ve broken it. But in this case, I’ll just believe that God is just, and will do better than I can.