The first and second commandments are hard to separate.
You shall have no other gods before me. You shall not make for yourself an idol in the form of anything (Ex 20:3,4).The requirements of these commandments still apply to Christians. Part of the act of becoming a Christian is a declaration that Jesus is Lord; that there is not other god that can match him. The warning about the dangers of idols and images is really important in a culture where image is everything.
However, these sins are no longer crimes punishable by civil authorities. In Israel, the death penalty was required for those who chose to worship other gods. As Israel had chosen God to be their King, following another God was a form of treason and the normal penalty for treason and sedition was death (Deut 13:12-16). Under the new covenant people freely choose the Lord as their God. His greatest gifts to us is freedom, so he will never force sinners to love him, if they are unwilling. God wants people to obey him, because they love him, not because they have to. The most that he will do to make them love him is the Holy Spirit’s stirring in their hearts. Following God’s example, we should never use political power to force people to believe in God.