Who is defining the Word?

1 John 4:16 (KJV)
¹⁶ And we have known and believed the love that God hath to us. God is love; and he that dwelleth in love dwelleth in God, and God in him.

You will hear people such as homosexuals quote this phrase “God is love” in an attempt to qualify their behavior as God accepted. The problem lies in the definition of terms and phrases in the bible being redefined by unqualified people who are attempting to twist scripture to propagate their own agenda.  They define love as being tolerant of their behavior without any pointing out of its errant lifestyle according to the Word. In their view, I as a Christian, am to love them meaning I am to accept them and treat them nicely and not mention their sin as such. However, biblical love will look at that person and confront their sin – not with the attitude of satisfaction in finding fault with them. It is looking at them with compassion not being able to bear the thought that they could spend eternity in Hell, and as a result I warn them of their sin due to my true love for them. Jesus loved people enough to confront their sin. When reading the account of the Samaritan woman in John 4, we will read that before she could be free, he had to expose her sin. Once he confronted her sin, she became a liberated woman. Whose definition of love am I going to believe – the bible’s or…?