God said to Abraham, it is because God credited the faith of Abraham, Abrahams belief in Him as righteousness, He said those who bless you I will bless and those who curse you I will curse. People don’t see rightousness as God see’s it so they are robbed from the blessing that is availaible to bless whom God has bless. And let me say if you bless one that lives under this same covenant as Abraham did the blessing return to you is a mega blessing, and a continueing mega blessing if you continue to bless one of these. If you are trying to bless one that is not one of these then you just won’t get that mega blessing from blessing them. But the biggest issue is, it is far more easier to curse what God has blessed and this is a real thing, somthing that one should seek out more, if you curse one that has the blessing of Abraham on them then it can be curtains either quicker or slower, I write this so you can be aware. The covenant that God made with Abrabam was God’s first steps of the redemption of mankind after the flood. Wake up to what you curse and awake to blessing what God has blessed. These things are very very real and are being magnified and increased and increased in full measure that will fill the earth. I say again in another way the thinking of man will curse what God has blessed it is just the way of man, so I suggest you get God’s thoughts so that you can take part of the blessing.