This article is the first in a series of three by Michael D'Antonio and Peter Eisner, the authors of the new book, " The Shadow President: The Truth About Mike Pence." The opinions expressed in this commentary are their own. View more opinion articles on CNN.

(CNN) Now familiar as a smiling, nodding presence at the President's side, Mike Pence was little known outside of his home state of Indiana when Donald Trump selected him as his running mate in 2016. A bit more than two years later, as he crisscrosses America to campaign for Republicans in the midterm elections, Pence is setting himself up to replace his boss if Trump leaves office early or does not seek re-election.

"Mike will be ready" is the line Pence's aides and allies use as they contemplate his place in a post-Trump world.

Pence would never admit this. He plays the part of unctuous toady so fully that the conservative writer George Will called him "America's most repulsive public figure." But don't be fooled. The vice president is doggedly pursuing his own ambitions on the side. The Oval Office has been his goal since high school. He has seeded the federal government with his loyalists and is building his own nationwide political organization.

He is acting, in fact, as if he is on a mission from God. Some may laugh, but many conservative Christians believe that God is merely using Trump to prepare the way for a so-called true man of faith. Pence's rise to power would affirm the " Cyrus prophecy, " which became a popular notion among Christian right circles when Pence joined the 2016 ticket.

Cyrus was a Persian king whom the Old Testament credits with returning the Jews to Jerusalem. He was a pagan who nevertheless served God. Right-wing evangelists such as Lance Wallnau cited that tale in 2016 when they declared that Trump -- a profane and sinful man -- could nevertheless do God's work and was thus worthy of conservative Christian votes. An estimated 80% of white evangelicals gave Trump their votes.

The story of Cyrus resonates with many right-wing Christians because they imagine themselves to be persecuted like the Jews of old. Despite their vast wealth, power and numbers, these believers cite developments such as same-sex marriage and the use of ecumenical phrases such as "happy holidays," instead of Merry Christmas, as evidence they are a minority under siege. They imagine themselves to be victims of a culture war and feel that something must be done to defend an old order that they once dominated.

Photos: Mike Pence's political life and career Photos: Mike Pence's political life and career Pence announces that the Centers for Medicaid and Medicare Services had approved the State's waiver request for the plan his administration called HIP 2.0 during a speech in Indianapolis on January 27, 2015. Hide Caption 1 of 31 Photos: Mike Pence's political life and career Pence, then the Republican candidate for Indiana's 2nd Congressional District, is surrounded by his wife, Karen, right, and family as he addresses supporters on November 7, 2000, in Columbus, Indiana. Pence defeated Democrat Robert Rock in the race to fill the seat vacated by David McIntosh, who held the position from 1995-2001. Hide Caption 2 of 31 Photos: Mike Pence's political life and career Pence and Republican Arizona Sen. Jeff Flake talk on July 10, 2002, during the markup of the bill which would establish the Department of Homeland Security. Hide Caption 3 of 31 Photos: Mike Pence's political life and career Pence, Reps. Carolyn B. Maloney, D-New York, and Christopher Shays, R-Connecticut, walk with a bipartisan group of members during a news conference on July 22, 2004, about the release of the 9/11 Commission report. Hide Caption 4 of 31 Photos: Mike Pence's political life and career From left, Reps. Ted Poe, R-Texas, Mike Pence, R-Indiana, Jeb Hensarling, R-Texas, and Jeff Flake, R-Arizona, attend a news conference to call for budget offsets to pay for the Hurricane Katrina relief and reconstruction effort. Hide Caption 5 of 31 Photos: Mike Pence's political life and career Pence speaks at a news conference on September 5, 2008, in Washington. Pence and other House Republicans called on then-House Speaker Nancy Pelosi to schedule a vote on energy legislation to help lower gasoline prices. Hide Caption 6 of 31 Photos: Mike Pence's political life and career Former Speaker of the House John Boehner hands a copy of the stimulus bill to Pence after the House of Representatives voted to pass it on February 13, 2009. The bill passed the House along a strict party vote of 246-183. Hide Caption 7 of 31 Photos: Mike Pence's political life and career Pence is joined by his wife, Karen, as he carries his ballot petition signatures to run for governor of Indiana into the Secretary of State's Election Division in Indianapolis on February 6, 2012. Hide Caption 8 of 31 Photos: Mike Pence's political life and career The three candidates for Indiana governor, Democrat John Gregg, left, Pence and Libertarian Rupert Boneham, gather after a debate in South Bend, Indiana, on October 17, 2012. Hide Caption 9 of 31 Photos: Mike Pence's political life and career Pence is sworn in as Indiana's 50th governor by Chief Justin Brent E. Dickson as Pence's wife, Karen, and his family look on during a ceremony at the statehouse on January 14, 2013. Hide Caption 10 of 31 Photos: Mike Pence's political life and career Pence checks off a milestone on May 29, 2013, for a new Ohio River bridge that will connect Indiana to Kentucky, just east of Louisville. Hide Caption 11 of 31 Photos: Mike Pence's political life and career Pence speaks during a memorial service for former Indiana Rep. Andrew Jacobs Jr. at the statehouse on January 3, 2014. Jacobs died on December 28, 2013, at age 81. Hide Caption 12 of 31 Photos: Mike Pence's political life and career Pence speaks during the leadership forum at the National Rifle Association's annual convention on April 25, 2014, in Indianapolis. Hide Caption 13 of 31 Photos: Mike Pence's political life and career Pence formally announces his re-election campaign in Indianapolis on June 18, 2015. The Indiana native, whose status as a national star among conservatives was battered by an outcry over the state's new religious objections law at the time, launched a re-election campaign focused on the state's economy and improving schools. Hide Caption 14 of 31 Photos: Mike Pence's political life and career Pence delivers his State of the State address to a joint session of the legislature at the statehouse on January 12, 2016. Hide Caption 15 of 31 Photos: Mike Pence's political life and career Pence joins 2016 Republican presidential candidate Donald Trump at a rally in Westfield, Indiana, on July 12, 2016. Hide Caption 16 of 31 Photos: Mike Pence's political life and career Pence shakes hands with Republican presidential candidate Trump after being newly selected as his vice presidential running mate on July 16, 2016, in New York City. Hide Caption 17 of 31 Photos: Mike Pence's political life and career Pence points to the crowd as he walks on stage to deliver a speech on the third day of the Republican National Convention on July 20, 2016, at the Quicken Loans Arena in Cleveland, Ohio. Hide Caption 18 of 31 Photos: Mike Pence's political life and career Pence introduces his running mate, Trump, at a campaign event at Youngstown State University on August 15, 2016, in Youngstown, Ohio. Hide Caption 19 of 31 Photos: Mike Pence's political life and career Pence looks on before the first presidential debate at Hofstra University in Hempstead, New York, on September 26, 2016. Hide Caption 20 of 31 Photos: Mike Pence's political life and career Democratic vice presidential candidate Tim Kaine, left, and Republican vice presidential candidate Mike Pence speak during their debate at Longwood University in Farmville, Virginia, on October 4, 2016. Hide Caption 21 of 31 Photos: Mike Pence's political life and career Pence runs onto the stage at a rally on October 25, 2016, in Marietta, Ohio. Hide Caption 22 of 31 Photos: Mike Pence's political life and career New vice president-elect Mike Pence and President-elect Donald Trump shake hands during an election night event at the New York Hilton Midtown in the early morning hours of November 9, 2016, in New York City. Hide Caption 23 of 31 Photos: Mike Pence's political life and career Pence listens as the President-elect speaks during a meeting of technology executives at Trump Tower on December 14, 2016, in New York City. Hide Caption 24 of 31 Photos: Mike Pence's political life and career Trump stands with Pence at a news conference at Trump Tower on January 11, 2017, in New York City. Hide Caption 25 of 31 Photos: Mike Pence's political life and career The vice president-elect arrives for the presidential inauguration of Trump at the Capitol in Washington on January 20, 2017. Hide Caption 26 of 31 Photos: Mike Pence's political life and career Vice President Mike Pence, his wife, Karen, and their daughter Charlotte arrive for a rally on the National Mall before the start of the 44th annual March for Life on January 27, 2017, in Washington, DC. Hide Caption 27 of 31 Photos: Mike Pence's political life and career Pence delivers a speech on the second day of the 53rd Munich Security Conference in Munich on February 18, 2017. Hide Caption 28 of 31 Photos: Mike Pence's political life and career Pence, his wife, Karen, and his daughter Charlotte lay a wreath at the International Memorial of the former Nazi concentration camp of Dachau in southwestern Germany on February 19, 2017. Hide Caption 29 of 31 Photos: Mike Pence's political life and career Pence speaks during the Conservative Political Action Conference on February 23, 2017, in National Harbor, Maryland. Hide Caption 30 of 31 Photos: Mike Pence's political life and career Pence speaks to reporters during a news conference on Capitol Hill following a policy lunch on March 7, 2017. Hide Caption 31 of 31

As a radio host, member of Congress and then governor of Indiana, Pence made himself the most successful conservative Christian politician of his generation. Indeed he says he is "a Christian, a conservative and a Republican in that order."

During 12 years in Congress he never authored a single bill, but he did become a prominent advocate for banning abortion, defunding Planned Parenthood and restricting marriage only to heterosexual couples. In his one term as governor he overstepped when he signed a bill -- the so-called Religious Freedom Restoration Act -- permitting discrimination against gay people, and was forced to seek a change in the law.

His rhetoric attacking abortion rights, adultery and even evolution (he says he doesn't believe in it) assured the Christian right that he was one of them.

When Trump offered Pence his spot on the ticket, the Republican Party's evangelical wing was over the moon. Pence was also a first-term governor facing a tough battle for re-election despite a longstanding and substantial GOP advantage in voter registration. His outspoken support for the Religious Freedom Restoration Act had alienated some centrist Republicans and, though Pence was genial enough, he was not the kind of campaigner who got folks fired up.

Offered a path out of struggling obscurity in Indiana, Pence didn't need a Bible prophecy to tell him it was OK to take the leap. He hitched his pious ambitions to a crude, twice-divorced, self-confessed sexual predator whose grasp of faith and Scripture appears nonexistent.

Pence's favorite Bible verse reads: "For I know the plans I have for you, plans to prosper you and not harm you, plans to give you hope and a future." He cites it when he discusses the opportunities that come his way, and to explain the confidence he brings to politics.

JUST WATCHED VP Pence full National Prayer Breakfast speech Replay More Videos ... MUST WATCH VP Pence full National Prayer Breakfast speech 28:23

Pence's theology says that God selects in advance which individuals will become believers and rewards their faith regardless of what they do. This belief allows for all sorts of bad behavior, if it can be framed as supporting the ultimate goal of promoting the evangelical agenda.

Pence's loyalty to the President, even after the "Access Hollywood" tape exposed Trump as a serial sexual harasser, baffled many. It was reported at the time that Pence considered trying to replace Trump at the top of the ticket, but in the end he held his place and his tongue. Pence's religion explains that choice, and his decision to abandon many of his previous positions on the issues, such as his opposition to banning Muslim visitors to America.

To understand how a seemingly pious politician such as Pence could join Trump and stick with him requires tracing the long path of his ambition. Pence wasn't always the rigidly moralistic and confident conservative evangelical he professes to be today. But he was, from the beginning of his adult life, a man who thought he was destined for the presidency.

This article is the first in a series of three by Michael D'Antonio and Peter Eisner, the authors of the new book, " The Shadow President: The Truth About Mike Pence.

An earlier version of this op-ed incorrectly indicated that President Trump was thrice divorced. He has been divorced twice.