It is if you believe lying is a sin.
A man is a man. Calling him a women is a lie.
A woman is a woman. Calling her a man is a lie.
One of the big ten.
"Thou shalt not bear false witness..."
“Thou shalt not bear false witness” forbids: “1. Speaking falsely in any matter, lying, equivocating, and any way devising and designing to deceive our neighbour. 2. Speaking unjustly against our neighbour, to the prejudice of his reputation; and (which involves the guilty of both).
Psalm 86:11
“Teach me, O Lord, your ways, that I might walk in your truth/faithfulness.”
Psalms 34:13-14 New International Version (NIV)
...keep your tongue from evil and your lips from telling lies. Turn from evil and do good; seek peace and pursue it.
Proverbs 12:22
22 Lying lips are an abomination to the LORD, but those who act faithfully are his delight.
Playing along with the lies and false religions of the land has the effect of normalizing it. Toady we are seeing a replay of the ancient evils of the OT. To which the Bible says:
Leviticus 18:30 KJV
30. Therefore shall ye keep mine ordinance, that ye commit not any one of these abominable customs,
which were committed before you, and that ye defile not yourselves therein: I am the LORD your God.
Proverbs 6:16-19 KJV
16. These six things doth the LORD hate: yea, seven are an abomination unto him:
17. A proud look, a lying tongue, and hands that shed innocent blood,
18. An heart that deviseth wicked imaginations, feet that be swift in running to mischief,
19. A false witness that speaketh lies, and he that soweth discord among brethren.
Do not contribute to the normalizing of evil in the land by playing along with it. If you cannot fight it, at least do not participate in it.