In our culture, love and acceptance are seen as synonymous. If you do not wholeheartedly agree with certain agendas, you are seen as hateful and bigoted. And yet, those same standards only apply one way. It is "love" to agree with the world, and "hate" to disagree, but it is also "love" for the world to disagree with your Christian values, and "hate" if they support you.
Let's take the popular example of the LGBT wedding cake debate. Why is it seen as hateful for a Christian to refuse to bake a cake for a gay "wedding", but not hateful to literally destroy their business because of that refusal? On the one hand, the LGBT people can just go to a different cake store. They lose nothing (in this life). They suffer nothing. The worst they'll get is hurt feelings. By contrast, if the business is attacked as a result, they lose a lot. Large amounts of money, possibly their beloved businesses, maybe even their homes depending on how severely crippled their finances are as a result. So, how is it considered hateful to simply disagree, but not hateful to actively seek to hurt people for not agreeing?
Furthermore, how is it in any way loving to participate in a sin ceremony? As Christians, we believe in a perfect and Holy God. We believe in sin, we believe in the consequences for sin, and we believe in the possibility of salvation. What you're effectively saying when you insist a Christian must support the LGBT agenda in order to be considered loving is that it is better to push someone into Hell than at least try to encourage them to come to Heaven. Is that loving?
In truth, no. Love, as the Bible describes it, does not take pleasure in sin. Instead, it rejoices with the truth (see 1 Corinthians 13). If you want to see what real love does, look to the cross. There, God Himself showed LGBT people exactly how much He loves them. Rather than instantly punish them for their evil, He instead punished Jesus. Every sin, not just sexual immorality, was nailed to the cross that day, and as a result, we can say the penalty has already been paid. Through faith in Christ, we can all inherit eternal life. That is love.