Hi Bella11,
I think that there is not only one person to marriage. I believe who God send more than one right person to us, and let us, so choose between them. However, this our choice shall be directed by the Holy Spirit, and this person who we choose, of course, to be a true servant of Jesus, a believer was born again.
If there is only one person, the servant of Jesus who are widow or widower would can not marry again, because they already there are married with the only person before.
God bless you,
Miss.