I am of the opinion that God could not, through Malachi, spell out the marriage covenant any clearer than He does in Chapter 2 of Malachi. God Himself is witness on the day of a wedding taking place.
He introduced the covenant. Through the marriage vows, your spouse becomes your 'covenant partner'. This is serious business in the eyes of God the Father.
God also commands us to keep a watch on our own spirit man and to be in subjection and under the control of His Spirit so that we may deal truthfully and lovingly with our spouse and in our marriage union.
Malachi 2: 14-16 AMP
14 Yet you ask, Why does He reject it? Because the Lord was witness [to the covenant made at your marriage] between you and the wife of your youth, against whom you have dealt treacherously and to whom you were faithless. Yet she is your companion and the wife of your covenant [made by your marriage vows].
15 And did not God make [you and your wife] one [flesh]? Did not One make you and preserve your spirit alive? And why [did God make you two] one? Because He sought a godly offspring [from your union]. Therefore take heed to yourselves, and let no one deal treacherously and be faithless to the wife of his youth.
16 For the Lord, the God of Israel, says: I hate divorce and marital separation and him who covers his garment [his wife] with violence. Therefore keep a watch upon your spirit [that it may be controlled by My Spirit], that you deal not treacherously and faithlessly [with your marriage mate].
Another warning comes from the author of the book of Hebrews chapter 13:
Hebrews 13:4 (NLT)
4 Give honor to marriage, and remain faithful to one another in marriage. God will surely judge people who are immoral and those who commit adultery.
Marriage is beautiful and blessed and when shared in union with and built upon the Word of God and the Holy Spirit, it is a magnificent and glorious gift.
Stay blessed and holy in your covenant,
In Christ our Covenant Partner
Pr. Paddick Van Zyl
*Scripture emphases mine