The same thing happened to McCain. Nobody trusted him about anything because he was always playing both sides for his own personal gain. If you convert to Judaism and then try to go back to the Church, it doesn't work. The Christians will always think of you as a Jew and the Jews will always think of you as a Christian. It is a no win.
The only path to respect is to pick a position and stick with it. Once you show that you have no moral foundation, then who can possibly trust you about anything?