Can a person reject the Virgin Birth and still be a Christian? The answer is no. The Virgin Birth was never meant to stand alone. It is not a random truth plucked from thin air. God never says, "Pick and choose what you want to believe." The story of Jesus is a seamless garment woven by the Holy Spirit. Take out his miraculous birth and you have ripped the whole garment to shreds.
Christianity is not just a collection of random truths, any one of which could be dropped with little harm. It is true, and truth is a whole. Consequently, a diminution at any point inevitably affects the rest, given enough time. When we begin to drop this doctrine or that doctrine, even though we cannot see at the time how it will affect the rest, it nevertheless does affect the rest.
History teaches us that when men begin to doubt the Virgin Birth, they do not stop there. One doubt leads to another until the Jesus they believe in is not the Jesus of the Bible. In truth, the Virgin Birth is no more miraculous than the Resurrection. They stand or fall together.
Do I understand it? No.
Do I believe it? Yes.
Why? Because the Bible teaches it and because it makes perfect sense.
Can we still believe in the Virgin Birth? We can and we must.