Louisiana Gov. Bobby Jindal wants a piece of Donald Trump. Jindal, whose presidential campaign has barely made a ripple as front-runner Trump has dominated news coverage with his uninhibited attacks on immigrants, women and the White House, aimed for Trump Thursday with a sweeping attack on his religious faith -- or lack thereof.

"You may have recently seen that after Trump said the Bible is his favorite book, he couldn’t name a single Bible verse or passage that meant something to him," Jindal said in remarks prepared for a speech to the National Press Club. "And we all know why: because it’s all just a show, and he hasn’t ever read the Bible. But you know why he hasn’t read the Bible? Because he’s not in it."

The speech came after Jindal's campaign manager Wednesday unfavorably compared the celebrity business mogul to notoriously troubled actor Charlie Sheen. "Charlie Sheen is clearly Donald Trump's spirit animal. Or maybe it's the other way around?" campaign manager Timmy Teepell said. The former "Two and a Half Men" star had a public meltdown in 2011.

The attacks are part of a concentrated effort to take down Trump and win over voters who have largely overlooked Jindal. "The summer of silliness will come to an end," the Louisiana governor's campaign said Wednesday. "Then it's time to get serious."

The fight went to Twitter Thursday morning, where Jindal called Trump a narcissistic clown amid a series of attacks. He also compared Trump to reality TV star Kim Kardashian during an interview on Fox. "Just because people like watching Kim Kardashian, we wouldn’t put her in the White House," he said.

In a NBC News/Marist poll of the Republican race released this week, Jindal tied with Sens. Ted Cruz of Texas and Marco Rubio of Florida at 4 percent. In a recent Monmouth University poll, he scored just 1 percent of the vote.