We believe that what we possess we don't ultimately own. God is merely entrusting it to us. And one of the conditions of that trust is that we share what we have with those who have less. So if you don't give to people in need you can hardly call yourself a Jew. Even the most unbelieving Jew knows that.
The time you spend alone with God will transform your character and increase your devotion. Then your integrity and godly behavior in an unbelieving world will make others long to know the Lord.