Pope John Paul II kept up his attack on liberation theology today in the mountain city of Merida, telling an audience of hundreds of thousands to keep faith with the church and to reject "materialistic" doctrines.

"To be faithful to the church is not to be dragged in by doctrines or ideologies contrary to church dogma, as certain groups inspired by materialism or dubious religious content would like," he said in Spanish in his homily at an outdoor mass in the regional capital of Venezuela's most religious zone.

Against a dramatic landscape of the snow-topped Andes, the pope received cheers of a flag-waving multitude. John Paul's attack on liberation theology, a mixture of Christian belief and Marxist analysis that would have the church take an active political role im combating social injustice, was his second since arrival in Venezuela Saturday.

In the homily at Merida, the pope stressed the importance of the church's spiritual mission over its social concerns. Faith, he said, "leads us to see earthly life as a preparation for spiritual life, like gold purified by fire."

Repeatedly invoking the name of St. Peter, traditionally the first bishop of Rome, Pope John Paul defended his authority and insisted that good Catholics must also be obedient Catholics.

"To be faithful to the church is to live in intimate communion with the pastors chosen by the Holy Spirit to rule the people of God. It is to accept with docility its teachings." he said.

Most recently, the pope's authority has been challenged in Nicaragua, where last week the Vatican gave four priests who had refused to step down from their posts in the Sandinista government a 15-day deadline do so.

On return to Caracas this evening, the pope revived the theme of radical theology in a talk with clergy, calling for "integral liberation."

Meanwhile, a Salvadoran bishop here for a conference said the pope had dined with Salvadoran Archbishop Arturo Rivera y Damas and Nicaraguan Archbishop Miguel Obando y Bravo last night.

Giving few details, the churchman said that the archbishops had briefed the pope on the situation in their respective countries.

He said Rivera y Damas was hopeful the "dialogue" between El Salvador's guerrillas and the government would continue in the near future. There has been speculation of a possible Vatican role in mediating a peace in Central America. Speculation grew after John Paul, officiating at a mass in Maracaibo, said he extended a special "embrace of peace" to the churches of El Salvador and Nicaragua.

On Tuesday, the pope flies to Ciudad Guayana, site of Venezuela's steel industry along the Orinoco River, and later departs for Ecuador.