Ye do err, not knowing the scriptures, nor the power of God. For in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven.
Human beings are spirits inside of a body.
Angels in heaven are spirits as well, but they do not have bodies. On the day of the resurrection, you will first be judged, then later God will give you a new body that is incorruptable. So, on the day of the resurrection, you will be like the angels in heaven, with a spirit, but without a body. Jesus was not necessarily saying that there is no marriage in heaven. The Sadducees were asking him about the resurrection, which they didn't even believe in.