Being a spirit is clearly something different from being made up of atoms, molecules, chromosomes, genes, and DNA. A spirit can take a form, and have an appearance, and even interact with us on a physical level; but beings such as angels (and of course God) are something far beyond what we are. We cannot use ourselves as a measure for determining what they are. Gabriel in Daniel 9 was able to travel from Heaven to earth where Daniel is in the short time it took for Daniel to pray his prayer (see Daniel 9:21-23). Assuming Heaven is an actual place somewhere in the universe, perhaps beyond the Great Nebula in Orion (said to be 1,344 light years from Earth, or 8,064,000,000,000 miles), this means that the angel Gabriel had to travel many, many times the speed of light--something that the laws of physics tell us is impossible for any physical object in our level of existence. So spirit has to be something significantly different from the physical matter that comprises us. And then consider that the Holy Spirit is able to be instantly omnipresent, anywhere in the universe, and that is something that is clearly beyond anything physical. But yet that does not mean the Holy Spirit is bodiless. We believe the Holy Spirit does have a body, can and has manifested Himself as having a body. At Jesus' baptism the Holy Spirit was manifested in bodily form as a dove (Matt. 3:16). So being spirit does not mean bodiless. It simply means an entirely different order of being from the physical realm. There is a different KIND of body. Angels cannot mate with humans (despite what some superficial readers of Genesis 6:4 may think), and the Son of God had no DNA to combine with Mary's DNA.