Is Jesus the ONLY way?

Simple answer: Yes

Long answer: Jesus said to him, "I am the way, the truth, and the life. No one comes to the Father except through Me." (John 14:6)

We can't earn our way into Heaven. God the Father is waiting for us in Heaven. Think of it this way: If your master said you had to fill in the ocean with dirt, could you? Holland has managed to push the ocean back to reclaim land, but it is small in comparison to what they have left in the Atlantic. Our good works are nothing but a buckets worth of dirt thrown into the ocean compared to how much we are indebted to God. Do not get me wrong; our good works are important.

A little more information on this verse may help you understand. Shepherds in Jesus' time would build a sheepfold out of mud bricks, often the only material available. They would tear off thorn bushes to put along the top of the walls similar to barbed wire fences today. Then the shepherd himself would sleep in the doorway. In other words he became the gate. Jesus is our gate. Try to get in any other way and you get the thorns.