Once saved always saved?
Catholics believe that the Elect have assurance of salvation but unless God reveals their Elect state to us we cannot identify them. On the other hand, some (not all) Protestants and “Bible only” Christians believe that once they have faith in Christ then they are one of the Elect and therefore have assurance of salvation. Verses that are generally quoted to support “once saved always saved” are:
All that the Father gives me will come to me, and him who comes to me I will not cast out. For I have come down from heaven, not to do my will, but the will of him who sent me; and this is the will of him who sent me, that I should lose nothing of all that he has given me, but raise it up at the last day.
My sheep hear my voice; and I know them, and they follow me; and I give them eternal life, and they shall never perish; and no one shall snatch them out of my hand.
For I am sure that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, nor height, nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord.
Catholic will reply that it is true that Christ will not cast out those who believe in Him and nobody can snatch them from Him but the verses do not rule out the possibility they are the ones who decide (using their freedom) to leave Him. In John 17:12 Christ said: While I was with them, I kept them in thy name, which thou hast given me; I have guarded them, and none of them is lost but the son of perdition, that Scripture might be fulfilled. Here Christ talked about his twelve disciples whom God the Father gave to Him. This means He would not cast them out and no one can snatch them from Him. However we know that one of them (Judas) later betrayed Him. Similarly Catholics understand Romans 8:38-39 as talking about external factors that are unable to separate us from God’s love; it does not support assurance of salvation as we can use our freedom (internal factor) to reject God. Consider this analogy: some countries in the world do not recognize dual (or more) citizenships. If we hold citizenship of that country, no one can snatch it from us – even committing crime will not make us lose our citizenship. Our citizenship is indeed secured but we will lose it if we decide (using your freedom) to take citizenship of other country.
Other argument to support assurance of salvation is since the Bible says those who become believers in Christ are adopted as sons of God (John 1:12, Romans 8:15, 23, Galatians 4:5 and Ephesians 1:5) then their salvation is assured because God won’t reject His sons. But Christians are not the only ones in the Bible whom God calls as sons. In Exodus 4:22-23 and Hosea 11:1, God also calls the Jews His sons. Romans 9:4 reaffirm their adoption as sons, i.e. they do not lose their son-ship in the new covenant. The Greek word translated as adoption or son-ship in Romans 9:4 is huiothesia. The same word is used in Romans 8:15, 23, Galatians 4:5 and Ephesians 1:5 to indicate son-ship of Christians. If being God’s adopted sons guarantees us heaven, then all Jews will go to heaven, just by being Jews, which is certainly not the case (Romans 11:26 says “and so all Israel will be saved” but hardly any will interpret it to mean all Jews will be saved. To see the context we need to read Romans 11:13-36). Furthermore Scripture says that whoever does not do right is no longer child of God, thus son-ship is not something that is always guaranteed once we believe in Christ.
By this it may be seen who are the children of God, and who are the children of the devil: whoever does not do right is not of God, nor he who does not love his brother.
1 John 3:10