It's just so unhelpful. Many truths of Christianity just can't be captured in a bumper sticker, and "Jesus Love Osama" (as in bin Laden) is one of those. Slogans often don't accurately translate the truthfulness of biblical teaching. This certainly isn't sharing the Gospel, as a spokesperson for the church claims. Here's why.
There's a biblical truth behind this: "Love your enemies, and forgive those who persecute you." (Matt. 5:44) This is a real challenge to our natural human tendencies for revenge (as opposed to justice, an important distinction). It would be a good thing to pray for bin Laden.
What would prayer for him involve? It could be that God would prevent his intentions from action or that he would be brought to justice. It could even be for his salvation. Could God forgive bin Laden? Sure. The salvation of every one of us sinners takes an intervention by God's grace. It would certainly be better for the world and for bin Laden individually if he accepted forgiveness for his sins. And the amazing thing is that Jesus' salvation is adequate to cover all sin.
But the message on the banner is incomplete. The Bible also tells us that God hates sinners and violence. (Psalm 11:5) The bad news - our complete and utter guilt for our sin - is part of the Gospel because the Good News makes no sense without the bad. God hates bin Laden. He hates all sinners.
Signs like this don't share the Gospel. They mislead because they are inadequate. And what's the point of putting up this sign? It's hard to imagine what the church thought it could accomplish. Christians share slogans too often, not all on signs. Instead of unhelpful and misleading slogans, we should equip ourselves to clearly explain the Gospel and the Bible so that people can understand. That doesn't guarantee they'll accept it - that's only the work of the Holy Spirit. But how many people haven't accepted God's offer because we haven't done a good job of explaining it? I fear too many. And I fear that some of the ridicule we receive is deserved because of our inadequacy in representing God's message.