Romans 7:2, it says: “A married woman is bound to her husband while he lives, but if her husband dies, she is released from the law of marriage.”
Marriage is a strong relationship between two people and have come to stay together forever. Marriage is something that the relationship stays provided the two couples are still alive. When a husband or wife dies, the surviving partner is no longer bound by that marriage covenant. Because of this, the Bible does not forbid remarriage after the death of a spouse. Instead, it gives believers the freedom to decide whether they wish to remain single or marry again.
In the bible, those who are widow and windower are expected to show compassion to them. These people experience loneliness and God understands what they're passing through. For this reason, the Bible does not condemn those who choose to remarry. At the same time, it also respects those who choose to remain single and dedicate their lives fully to serving God.