Bible readings: Psalms 103:13-14, Romans 7:3
The Bible doesn't object to a man or a woman remarrying after the death of their spouse. They are at liberty to remarry after the death of their partner. There's no law that kicks against this, according to God's government.
People involved in this situation often have a hard time remarrying. The reason being that they were too emotionally attached to their partner when they were still alive. This could have left them in so much grief that they couldn't bear to accept the loss of their partner.
God absolutely understands the state of such a person going through that phase. If there is one that can absolutely understand the deepest of our emotions, be it pain or otherwise, it is God. Let's examine the scripture below:
Psalms 103
13 - Like as a father pitieth his children, so the LORD pitieth them that fear him.
14 - For he knoweth our frame; he remembereth that we are dust.
The loss of a companion can be really painful. In the days of the person's youth, he or she might not feel the need of remarrying due to certain factors. It could be that the person has kids already and is too concerned with looking after them.
And also, the person may be so okay with the company of the children that he or she does not see the need of remarrying at that time. It could also be that the person is occupied with work and other activities. The person could console himself or herself with the company of friends.
But as time goes on and the person begins to advance in age, things begin to change. His children gradually begin to depart from him. Some of them might be too engaged in their academics or work, or may even have their own families.
They may no longer be as strong as they were in the days of their youth and may not be able to continue in their occupation. At this point, they may need to retire. With all these factors, it could lead to severe loneliness. Times like this could really stir up the need for a companion.
The bond between a husband and a wife is broken the moment one of the partners dies. Therefore, this provides the liberty of the man or the woman to remarry. We see this in Romans 7:3. The marriage after the death of a spouse is totally accepted by God.