The pastor was right, there are messages in the Bible that are sufficiently reassuring.

You don't have to pull crowds to the church as if it is a social arena, where the motive is to generate money. Crowed assembly is not an assurance of God presence.

The church is a spiritual forum to worship God and receive sobering messages that can help us become good citizens.

What ever makes you a good christain,makes you a good citizen.

I don't encourage sitting in the councils of mockery.

The truth is bitter

Since you confirmed that you heard a pastor speak that 'every idle word is a sin', you heard it right. Whatsoever the Bible condemns is sin, because that is the word of God which is God himself speaking. But the devil has a way of confusing Christians by giving wrong ideas, just as telling Christians that everything cannot be rigid in the church, that there should be moments of jokes, that inviting worldly people to minister in the church does not matter.

I Don't know what you mean By Sin But I'll say a Satirstical Joke...

"Religion has actually convinced people that there's an invisible man living in the sky who watches everything you do, every minute of every day. And the invisible man has a special list of ten things he does not want you to do. And if you do any of these ten things, he has a special place, full of fire and smoke and burning and torture and anguish, where he will send you to live and suffer and burn and choke and scream and cry forever and ever 'til the end of time!

But He loves you. He loves you, and He needs money! He always needs money! He's all-powerful, all-perfect, all-knowing, and all-wise, somehow just can't handle money!"
- George Carlin