No, we won't just be spirits, without any form or substance. God gave our bodies to us, and some day God will unite our souls with our new bodies–bodies that will never become sick or grow old.
Those bodies will be far more glorious than anything we can ever imagine right now. The Bible compares this to the planting of a seed–a seed that may be very small and insignificant and unimpressive, but which sprouts and brings forth something beautiful and glorious. The Bible says, "So it will be with the resurrection of the dead. ... it (the body) is sown in dishonor, it is raised in glory" (1 Corinthians 15:42-43).
What will we look like in heaven? The Bible doesn't tell us exactly–and the reason, I believe, is because we can't even begin to imagine what we will really be like then. But the Bible does tell us this: Our new bodies will be like the body Jesus had after His resurrection. The Bible says, "Just as we have borne the likeness of the earthly man, so shall we bear the likeness of the man from heaven" (1 Corinthians 15:49).
The most important truth, however, is this: This life is not all, but ahead of us is heaven if we know Christ. Do you have that hope in your heart? You can, by giving your life to Jesus. Then you too will have "a living hope through the resurrection of Jesus Christ" (1 Peter 1:3).