I think I will stay away from the debate of whether one can lose their savation, I don't think it is the topic of this thread. Although I do have a stance that once saved always saved.
Regarding the topic of reconciling Paul and James.
To fully understand what Paul tells us within his writings, it is important to first know to whom Paul is writing and what misconceptions these readers had in Paul’s day. Many times Paul writes to the Jewish people and many of these times he writes particularly to Jewish Christians. One of the misconceptions of many of the Jewish people of Paul's day was that to be in right standing with God one first does works toward obeying the Law. This is one reason he spends a lot of time on this issue within his writings.
In his letter to the Romans, Paul tells his readers that his prayer to God is for Israel to
“be saved” (Rom 10:1). In the very next verse Paul lays out how the Jewish people were
“ignorant” (Rom 10:2a) of God’s righteousness. To be ignorant is to lack knowledge about something, in this case, it was the lack of knowledge of how to be in right standing with God. He goes on to say that the Jewish people
“established their own” (Rom 10:2b) criteria for justification, i.e., right standing with God, and thereby failed to submit to the
“righteousness of God” (Rom 10:2c).
So where did the Jewish people of Paul’s day get justification wrong? Apparently many of the Jewish people of the day believed that satisfying the Law justifies and puts one in right standing. Therefore, they believed that if one keeps the Law, one is justified and in right standing in the eyes of God. Many of the Jewish people lived by a formula that apparently looked something like this...
works → satisfying the Law → brings right standing with God
But Paul had told his readers earlier in his letter to the Romans that this is not the case at all, that is, it is incorrect to think that justification
starts with works toward satisfying the Law. And Paul speaks directly to this point in Romans chapter 3.
(Rom 3:28 NKJ)
28 Therefore we conclude that a man is justified by faith apart from the deeds of the law.
In Romans 1:17 he had written,
“the righteousness of God is revealed from faith to faith; as it is written, ‘The just shall live by faith’”. In Galatians Paul also writes,
“no one is justified by the law in the sight of God” (Gal 3:11a) and goes so far as to say it should be
“evident” (Gal 3:11b). But the Jewish people had been living by works first and not faith, but as Paul points out,
“The just shall live by faith” (Rom 1:17, Hab 2:4, Gal 3:11, Heb 10:38).
Many people, it would seem, stop there regarding Paul and his doctrine of justification. However, Paul actually never stops with being justified by faith first. Within Paul’s writings he never stops with just the assertion that one is justified before God by grace, blood, and faith (Rom 3:24, 5:1, 5:9). He is very consistent in his letters to go on to the next step of the equation after being in right standing before the eyes of God by faith first.
In Paul’s vernacular this next step is expressed as,
“therefore…we also should walk in newness of life” (Rom 6:4) and present ourselves
“to God as being alive from the dead” (Rom 6:13), presenting our
“members as slaves of righteousness for holiness” (Rom 6:19) which is our
“reasonable service” (Rom 12:1).
Paul tells us that there is a
“reasonable service” (Rome 12:1) that all that believe should
“walk in” (Rom 6:4). In Romans chapter 6, Paul writes that we are not called and set apart that we might continue in sinful deeds (Rom 6:1-2). Paul, like all of the NT, is teaching that by grace, blood, and faith we are
“made alive by the Spirit” (1Pet 3:18, 1Cor 15:22, Col 2:13, Eph 2:1) and
“those who have believed in God should be careful to maintain good works” (Tit 3:8) for we were
“created in Christ Jesus for good works” (Eph 2:10b) and we
“should walk in them” (Eph 2:10c).
Clearly Paul is trying to teach the correct formula that many of the Jewish people of the day had gotten wrong. Paul has been adamant that the correct formula to be in right standing in the eyes of God starts with grace, blood, and faith (Rom 3:24-24, Rom 51:9). However, that right standing, according to Paul, should result in being
“made alive by the Spirit” (1Pet 3:18, 1Cor 15:22, Col 2:13, Eph 2:1) and because of this we should present as
“being alive from the dead” (Rom 6:13). This being alive from the dead is exactly what
James is referring to when he wrote,
“faith was working together with his works” (Jam 2:22) .
The formula that Paul lays out in his writings is something like this,
grace/blood/faith → right standing → living sacrifice (Active faith) → good works
That is, grace, blood, and faith lead to right standing. That right standing should naturally lead to an active faith that works within that right standing which is the giving of one's self as a living sacrifice. This active, living sacrice unto God works togther with the Spirit and should naturally produce good works (what I like to call Fruitful-works).
James is simply telling his readers, in the book of James, that to be justified in the eyes of the Lord is to be in right standing and that good standing encludes walking in that right standing (Eph 2:10c). And if you think being in right standing stops at faith and does not include walking in that good standing (good works) then your faith is a dead faith.