No, its not calling God a liar.
Its calling who ever wrote whatever bit of the Bible you think condemns homosexuality, wrong.
Big difference. The Bible was not written by God, nor does it even claim to be. Why you seem to think it is is quite beyond me.
False..
"
Jesus replied, "You are in error because you do not know the Scriptures or the power of God."
"I, Daniel, understood from the Scriptures, according to the word of the LORD given to Jeremiah the prophet, that the desolation of Jerusalem would last seventy years."
"You diligently study the Scriptures because you think that by them you possess eternal life. These are the Scriptures that testify about me,"
"
Jesus answered them, "Is it not written in your Law, 'I have said you are gods'? If he called them 'gods,' to whom the word of God came—and the Scripture cannot be broken— what about the one whom the Father set apart as his very own and sent into the world? Why then do you accuse me of blasphemy because I said, 'I am God's Son'?"
"Bear in mind that our Lord's patience means salvation, just as our dear brother Paul also wrote you with the wisdom that God gave him. He writes the same way in all his letters, speaking in them of these matters. His letters contain some things that are hard to understand, which ignorant and unstable people distort, as they do the other Scriptures, to their own destruction."
"All Scripture is
God-breathed, and is useful for teaching, rebuking, correcting, and training in righteousness."
"Above all, you must understand that
no prophecy of Scripture came about by the prophet's own interpretation. For prophecy never had its origin in the will of man, but men spoke from God as they were carried along by the
Holy Spirit."
Need I go on?