I was just testing to see if my account was deleted yet and saw your post. I don't know these people or their affiliations but as far as the song goes I can't tell which part of the song is evil (the song Yes and Amen"
Since Paul says,
"our word toward you was NOT yea and nay"
2 Cr 1:18 But as God is true, our word toward you was not yea and nay.
Again, "not yea and nay, but in him was yea"
2 Cr 1:19 For the Son of God, Jesus Christ, who was preached among you by us,
even by me and Silvanus and Timotheus, was not yea and nay, but in him was yea.
Again, even "all the promises of God in him are yea, and in him Amen"
2 Cr 1:20 For all the promises of God in him are yea, and in him Amen, unto the glory of God by us.
Confidence also in him when asking anything according to his will is shown here
1 John 5:14 And this is the confidence that we have in him, that, if we ask any thing according to his will, he heareth us:
1 John 5:15 And if we know that he hear us, whatsoever we ask, we know that we have the petitions that we desired of him.
Jesus said,
Mat 21:22 And all things, whatsoever ye shall ask in prayer, believing, ye shall receive.
John 14:13 And whatsoever ye shall ask in my name, that will I do, that the Father may be glorified in the Son.
And again,
John 14:14 If ye shall ask any thing in my name, I will do it.
Showing in these again, "not yea and nay, but rather in him yea"
And no doubt whenever Ye ask, and receive not James adresses this also
James 4:3 Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts.
Not sure where the song was advocating lusts in its lyrics I looked up the Yes and Amen Lyrics
Found here
Jesus Culture (Ft. Chris McClarney) – Yes and Amen
As far a the song goes I can't find anything particularly evil in the words of the song as posted in that link
In respects to experience, as Br Bear touched upon, that should not be above the word of God but it is in the word of God
Paul said,
Romans 5:3-5 And not only so, but we glory in tribulations also: knowing that tribulation worketh patience;
and patience, experience; and experience, hope: and hope maketh not ashamed; because the love of God is shed abroad in our hearts
by the Holy Ghost which is given unto us.
The word of God itself speaks of experience