TAUNTON, MASS. ? A religious sect leader who said he was following instructions from God when he let his infant son slowly and painfully starve to death was convicted of murder Friday and sentenced to life in prison without parole.

The jury took 6 1/2 hours to find 29-year-old Jacques Robidoux guilty of first-degree murder. His son, Samuel, was fed only his mother’s breast milk for 51 days and died in 1999, three days shy of his first birthday.

During the trial, Robidoux said his sister had received a vision from God telling the couple to stop feeding the baby solid food.

Robidoux choked back tears as he described how Samuel went from a healthy, 10-month-old boy taking his first steps to a baby so withered he could no longer even crawl. His tiny bones were visible, and he cried in pain.

But Robidoux, whose sect rejects modern medicine and government, said he believed that the sight of Samuel’s misery was a test of the family’s will from Satan and that a miracle would save the boy.

Prosecutors used as evidence against Robidoux a journal in which he documented the boy’s slow death.

“It was as atrocious an act as you can have when a parent, two parents in this case, kill their child, not in a drug-induced haze, not in a violent rage, but as coldly as one could commit such a horrendous act day in, day out, for 51 days,” prosecutor Walter Shea said.

Robidoux’s wife, Karen, 26, faces trial Sept. 3 on a second-degree murder charge.