Q. If God is an "all-loving" God, why does He cast those to hell who do not know Him? Does that include people in third world contries as well?
2 Thess 1:5-10
5 This is a plain indication of God's righteous judgment so that you will be considered worthy of the kingdom of God, for which indeed you are suffering. 6 For after all it is only just for God to repay with affliction those who afflict you, 7 and to give relief to you who are afflicted and to us as well when the Lord Jesus will be revealed from heaven with His mighty angels in flaming fire, 8 dealing out retribution to those who do not know God and to those who do not obey the gospel of our Lord Jesus. 9 These will pay the penalty of eternal destruction, away from the presence of the Lord and from the glory of His power, 10 when He comes to be glorified in His saints on that day, and to be marveled at among all who have believed–for our testimony to you was believed.
First of all, note that in verse 5 the scriptures say that God has "righteous judgment." He will make no mistakes. He has all knowledge. We may think that we know something, or understand, but he has perfect knowledge and will make no mistakes. God has the right to bring people into judgment, because he knows the condition of their hearts, and he also knows on an individual basis the opportunities that people have had to either obey Him, or disobey.
In verse 8 when the scripture says "dealing out retribution to those who do not know God" this is a reference to those who "do not know God as He should be known." God desires all men to be saved:
1 TiM 2:4
"who desires all men to be saved and to come to the knowledge of the truth."
The way we come to know God is through the teaching of the Scriptures (Rom. 10:17). How do you know what opportunities a person in the 3rd world has had to either accept or reject God? You don't! I don't! But God does, and he will make no mistakes. Read the following passage very carefully.
18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men who suppress the truth in unrighteousness, 19 because that which is known about God is evident within them; for God made it evident to them. 20 For since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through what has been made, so that they are without excuse. 21 For even though they knew God, they did not honor Him as God or give thanks, but they became futile in their speculations, and their foolish heart was darkened. 22 Professing to be wise, they became fools, 23 and exchanged the glory of the incorruptible God for an image in the form of corruptible man and of birds and four-footed animals and crawling creatures. 24 Therefore God gave them over in the lusts of their hearts to impurity, so that their bodies would be dishonored among them. 25 For they exchanged the truth of God for a lie, and worshiped and served the creature rather than the Creator, who is blessed forever. Amen.
God has the right to judge the world because he has given adequate proof of his existence (Rom. 1:19-20). If a person, anywhere in the world wants to know more about the Creator of the Universe, God himself will see to it that that person has the opportunity to hear the gospel message from one of his servants, or through some other means. It is not our job to question Him, it is our job to sow the seed of the Word of God around the world to insure that all have the opportunity to hear.