God invites people of all nations to draw close to him in prayer.
"O Hearer of prayer, even to you people of all flesh will come."
(Psalm 65:2)
However, he does not listen to all prayers. For instance, when the Israelites persisted in badness, God refused to hear their prayers.
"Where else will YOU be struck still more, in that YOU add more revolt? The whole head is in a sick condition, and the whole heart is feeble." (Isaiah 1:5)
The prayers of a man who mistreats his wife can be hindered too.
"YOU husbands, continue dwelling in like manner with them according to knowledge, assigning them honor as to a weaker vessel, the feminine one, since YOU are also heirs with them of the undeserved favor of life, in order for YOUR prayers not to be hindered." (1 Peter 3:7)
But God will hear the prayers of gross sinners if they are truly repentant.
"And Ma‧nas′seh kept seducing Judah and the inhabitants of Jerusalem to do worse than the nations that Jehovah had annihilated from before the sons of Israel.
And Jehovah kept speaking to Ma‧nas′seh and his people, but they paid no attention. Finally Jehovah brought against them the chiefs of the army that belonged to the king of As‧syr′i‧a, and so they captured Ma‧nas′seh in the hollows and bound him with two fetters of copper and took him to Babylon. And as soon as it caused him distress, he softened the face of Jehovah his God and kept humbling himself greatly because of the God of his forefathers. And he kept praying to Him, so that He let himself be entreated by him and He heard his request for favor and restored him to Jerusalem to his kingship; and Ma‧nas′seh came to know that Jehovah is the [true] God." (2 Chronicles 33:9-13)
(Based on the Watchtower, Sept. 1, 2011, page 16)
