Seven Commandments of the Noahide Children

Judaism has 7 commandments that it requires of all Gentiles.
And the role of the Jews in the world is to lead all the Gentiles to observe these commandments and to be a light to the Gentiles.
One of these commandments is the prohibition of idolatry – a large portion of Gentiles believe in idolatry, in fact most Gentiles believe in it. So Judaism essentially wants to act in a missionary manner in order to promote the Noahide commandments and prohibit idolatry, which is the accepted belief in the world today.
 
So how can one claim that Judaism is a religion of morality and peace if Judaism requires Gentiles to change their faith?
How can the contradiction between various Jewish commandments that speak of morality and a good life be reconciled, and missionary activities and changing the popular lifestyle of Gentiles?