Mal 2:10 Have we not all one Father? Has not one God created us? Why then are we faithless to one another, profaning the covenant of our fathers?
Corrupt practices are the genuine fruit and product of corrupt principles. Hearts not surrendered to God are left to be governed by selfishness, jealousies, hatred, anger, bitterness, malice, pride etc.
Now, in these verses, we find men dealing falsely with one another, and it is because they have a low view of God and think falsely of their God. It cannot be expected that he who is false to his God should be true to others. They dealt treacherously with God, refusing to serve Him faithfully in giving themselves and their offerings to Him. Because of this, their consciences were suppressed and a door was opened to all manner of injustice and dishonest practices which is not God’s way. To compromise your morals is to open doors to acceptance of anything and Jesus said, “A good tree cannot bear bad fruit, nor can a bad tree bear good fruit.” (Mat 17:18).
In addition to this vs in Malachi, the bonds of relation and natural affection of love for one another were broken. One true test of love is found in 1Jn 4:20 “If anyone says, “I love God,” and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen.” The true test of love is not by what we say but how we live.