This message is not welcome inside the church.
Nor would this truck be allowed to park in the church parking lot. It sends the wrong message. Some would go so far as to place a gay affirming sign out front in order to sweeten the invitation.
A Pastor once met with me and expressed concern that I did not show the love of Christ in a video we posted in which we reminded some Mormons with the words of Apostle Paul in Galatians chapter one that they were under a curse for believing and promoting Joseph Smith's nonsense. Apparently when Jesus sent out his disciples they were not very loving either when they responded to unbelievers by kicking the dust off of their feet against them and claimed that it would be more tolerable for Sodom in the day of judgment than for their city (Luke 10:12).
In some parts of the world Christians are being martyred for their uncompromising faith but in America if a church gets merely a nasty phone call about the gospel the church will immediately begin to backpedal to appease the Devil's little messengers. Sometimes the Pastor is accommodating his board of elders who are weak-willed and have control over the purse strings and able to squeeze him financially. In some parts of the world Christians have stood firm in their faith as their children were slain before their very eyes. But in America if the children receive a little peer-pressure at school the Pastor is likely to lose members if he speaks too boldly in public.
Apostle Paul wrote to a young Pastor named Timothy telling him that God did not give us a spirit of fear and encouraged him to do the work of an evangelist. Evangelists are not welcome in many churches today because they ruffle feathers and make people uncomfortable.
"For the time will come when they will not endure sound doctrine; but wanting to have their ears tickled, they will accumulate for themselves teachers in accordance to the own desires; and will turn aside to myths." (2 Tim. 4:3)
Few churches teach anything on apologetics in order to equip their people to defend their faith therefore when some false gospel shows up like "The Shack" they have no idea what to say or do. Even the more obvious cults are a mystery to many church folks and as long as the cultist says something positive about Jesus they simply smile and remain silent.
Evangelism for many churches is watered down to giving out bottles of water with something written on it about God's love. Please don't mention that the wages of sin is death, that is way too negative.