One cannot be an effective part to two opposite kingdoms.
Jesus said a man cannot serve two masters. Matthew 6:24, No man can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other. Ye cannot serve God and mammon.
James, one of the apostles, asked it sweet and bitter water could come from the same fountain. James 3:11, Doth a fountain send forth at the same place sweet water and bitter?