God is not a god, he is the God. There are societies and religions all over the world that worship all sorts of gods. There are the gods of Greek mythology and there are the many gods of various indigenous tribes around the globe. But Christians are different in that we believe the God we serve is not a god, but the one true God. He is the Creator, not something created.
Joshua, one of the early leaders of the people of God said it this way.
Now fear the Lord and serve him with all faithfulness. Throw away the gods your forefathers worshiped beyond the River and in Egypt, and serve the Lord. But if serving the Lord seems undesirable to you, then choose for yourselves this day whom you will serve, whether the gods your forefathers served beyond the River, or the gods of the Amorites, in whose land you are living. But as for me and my house, we will serve the Lord (Joshua 24:14-15).
So you have to decide: God is either the God, or just a god among many other gods. He says he is the God. If so, then there can be no other gods in his place.
Jesus is not a way to heaven. He is the way to heaven. This is the claim that Jesus made.
I am the way, the truth, and the life. No one comes to the Father except through me (John 14:6).
These are not popular choices in a world that seems to thrive on being able to choose the god or path that fits you best. These are not claims that Christians make. These are claims that God and Jesus have made. We Christians have chosen to believe them.