He said he observed change in Mother Teresa. He said she had thought she needed to convert people but later felt a calling simply to love them. She said God would convert them through love.

"Love of course is the biggest magnet to poor people to the Lord, without forcing them. That's what she did her whole life long. She loved them and her love for them practically converted them, or gave them the chance to be converted," Msgr. Maasburg said.

He said her day-to-day life always included a kind of internal dialogue with Christ, infusing her Catholic work with faith in Christ's real presence in the world.

"For her, there was the same Christ present in the Eucharist as in the poorest of the poor, and you could love Christ only if you loved them," he said.

Msgr. Maasburg said as she struggled with her personal connection to God she experienced not atheism, but profound faith. He used an analogy created by St. John of the Cross to explain her ordeal. A collection of letters she had written about a "crisis of faith" she went through was published in 2007.

"Developing in a spiritual life is like coming out of the darkness, the darkness of sin. When you get in the half-light of the morning dawn of sanctity, then you feel two sides. You feel on one side you are sinful, and on the other side are already cleansed through the love of Christ," he said.

He said she moved into a kind of union with God through her faith, which changed her perspective.

"When you unite with God, there is a next stage where you exit into the open. You see. You are like the sun. When from the dark or half-dark you exit, you enter the sun then you do not see anything anymore," he said. "The eyes are not capable of taking that in."