"Believe as you believe, and allow others the same?"

Sorry, but I have seen no passages in God's Word that in any case validates that thought.

As a matter of fact, the opposite is stated. several times...

Matt 15:18-20
18 But the things that come out of the mouth come from the heart, and these make a man 'unclean.'
19 For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false testimony, slander.
20 These are what make a man 'unclean';

Ps 53:2-4
2 God looked down from heaven upon the children of men, to see if there were any that did understand, that did seek God.
3 Every one of them is gone back: they are altogether become filthy; there is none that doeth good, no, not one.

4 Have the workers of iniquity no knowledge? who eat up my people as they eat bread: they have not called upon God.
(KJV)

Rom 3:10-19
10 As it is written, There is none righteous, no, not one:
11 There is none that understandeth, there is none that seeketh after God.
12 They are all gone out of the way, they are together become unprofitable; there is none that doeth good, no, not one.
13 Their throat is an open sepulchre; with their tongues they have used deceit; the poison of asps is under their lips:
14 Whose mouth is full of cursing and bitterness:
15 Their feet are swift to shed blood:
16 Destruction and misery are in their ways:
17 And the way of peace have they not known:
18 There is no fear of God before their eyes.
19 Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God.
(KJV)

1 Cor 6:4-10
4 If then ye have judgments of things pertaining to this life, set them to judge who are least esteemed in the church.
5 I speak to your shame. Is it so, that there is not a wise man among you? no, not one that shall be able to judge between his brethren?
6 But brother goeth to law with brother, and that before the unbelievers.
7 Now therefore there is utterly a fault among you, because ye go to law one with another. Why do ye not rather take wrong? why do ye not rather suffer yourselves to be defrauded?
8 Nay, ye do wrong, and defraud, and that your brethren.
9 Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind,
10 Nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God.
(KJV)

Did God allow the Scribes and Pharisees their thoughts when he said unto them....

John 8:41-45
41 Ye do the deeds of your father. Then said they to him, We be not born of fornication; we have one Father, even God.
42 Jesus said unto them, If God were your Father, ye would love me: for I proceeded forth and came from God; neither came I of myself, but he sent me.
43 Why do ye not understand my speech? even because ye cannot hear my word.
44 Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.
45 And because I tell you the truth, ye believe me not.
(KJV)

Yea, rather than accept the evil of man's inhumanity, the evil of his thoughts, God's people are to resist it in the Spirit of God, with deeds and prayer.

When one extends validity to evil thoughts by "allowing" it, and failing to speak against it at every opportunity, one becomes captive to the thoughts of Satan.

"come out from among them, and be ye separate", sayeth the Lord.

1 Cor 3:16-21
16 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?
17 If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are.
18 Let no man deceive himself. If any man among you seemeth to be wise in this world, let him become a fool, that he may be wise.
19 For the wisdom of this world is foolishness with God. For it is written, He taketh the wise in their own craftiness.
20 And again, The Lord knoweth the thoughts of the wise, that they are vain.
21 Therefore let no man glory in men. For all things are yours;
(KJV)

So we are supposed to "allow" evil thoughts? I think not.

Perhaps the postmark on the letter should be reexamined...