Gods word is always complete and whenever we are in confusion we should never look back but always keep dwelling in God's word.
Marrying someone else after the death of such person spouse was said to be supported by God word because sometimes God knows that we such person might feel lonely , therefore will be in need of someone to talk to and to share his or her burden with, therefore marrying someone else is not considered as sin but is been concluded by the person if she or he actually wants to remarry.
It is important that we do not go astray from the things of God because probably because of the lost of ones spouse rather it is the time to be consistent about the things of God and keep consoling ourselves in Christ Jesus name Amen and in all getting married too to someone who is endowed with God's things.