“No one can serve two masters; for either he will hate the one and love the other, or he will be devoted to one and despise the other. You cannot serve God and wealth.”
Matthew 6:24
You cannot be bound equally both to God and to your confidence in wealth. One will always take precedence over the other, and the results of following either will be evident in your life.
The issue that Yeshua focuses on is not necessarily the results of following either (which are evident throughout the biblical writings), but the complete inability of humans to multi-task loving God in among other responsibilities in this life. We all have necessary obligations in life, but if our over-arching purpose for everything we do does not rest in God and his kingdom, then we have by default chosen to place our trust in the other option.
According to the New Testament writings, covetousness is equated with idolatry (Colossians 3:5). When viewed from this perspective, it is clear that God cannot be worshipped among any other gods, as one of many.
Yeshua makes it clear that every choice in life will fall under one heading or the other, God or worldly wealth, and whichever choice is made is a determination of which deity is being trusted.
The Core of the Bible 