There are certain scriptural doctrines a couple should be aware of and should not neglect as long as their marriage is involved. One of the reasons why they should live by such standards is because it can cause a form of barrier of their prayers getting answered if they refuse to live by them.
As a husband, it is important to know that there are certain behaviours that God expects from you towards your wife and also certain behaviours towards your wife He forbids. The same thing is applicable to the woman. We go through a passage in 1 Corinthians 7:3-5 which highlights God's ordinances pertaining to marriage.
One of the things to note as a wife is that your body belongs to your husband totally and you should not deny him of it whenever he is in need, likewise the husband. The joining together of the both of them one.
Matthew 19:6 - Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder.
By the reason of marriage, your body belongs to your spouse just as much as it belongs to you, that why you should never hold it back from him or her. Ignorance of these things could hinder their prayers from being answered, that's why a couple should endeavor to observe them.