Hi Tim,
Glad to share the same first name with a brother in Christ.
I will try to respond to your points below.
Originally posted by Tim:
Secondly, I believe you need to consider the historical setting of the scriptures you are referencing which seem to indicate that one can lose his salvation. The Jews of the first century were in a unique position in God's timetable. They were God's people by birth, but apart from a spiritual new birth, each would lose his place in God's favor and instead face His judgment. These scriptures were written to them to explain their precarious position--a position that true believers of our day are not in. We are secure in Christ.
I will agree that the historical writing of the letter of Hebrews was to Jewish people. They were, as the text indicates Jewish believers. The author of Hebrews goes to great pains to show the superiority of Christ's sacrifice to the old sacrificial system. There are several verses in Hebrews that indicate that these were believers.
For instance:
Therefore, holy brothers, who share in the heavenly calling, fix your thoughts on Jesus, the apostle and high priest whom we confess. Hebrews 3:1 NIV
See to it, brothers, that none of you has a sinful, unbelieving heart that turns away from the living God. Hebrews 3:12 NIV
I believe that the issue is not that they are being exhorted to accept Christ as their savior, but that they are being exhorted not to fall away.
It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit, 5 who have tasted the goodness of the word of God and the powers of the coming age, 6 if they fall away, to be brought back to repentance, because to their loss they are crucifying the Son of God all over again and subjecting him to public disgrace. Hebrews 6:4-6 NIV
If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left, 27 but only a fearful expectation of judgment and of raging fire that will consume the enemies of God. 28 Anyone who rejected the law of Moses died without mercy on the testimony of two or three witnesses. 29 How much more severely do you think a man deserves to be punished who has trampled the Son of God under foot, who has treated as an unholy thing the blood of the covenant that sanctified him, and who has insulted the Spirit of grace? 30 For we know him who said, "It is mine to avenge; I will repay," and again, "The Lord will judge his people." 31 It is a dreadful thing to fall into the hands of the living God. Hebrews 10:26-31 NIV
Originally posted by Tim:
Thirdly, I ask the obvious question--How can anyone lose eternal life? If one lost it, it obviously wasn't eternal. The scriptures clearly teach that eternal life a a present possession of believers, rather than something conferred to us upon death. So one either has it forever, or never had it.
Eternal life is a promise for those who endure until the end. It is something that you are rewarded with at the end of this age whether that is for you at death or at Christ’s coming.
"I tell you the truth," Jesus replied, "no one who has left home or brothers or sisters or mother or father or children or fields for me and the gospel 30 will fail to receive a hundred times as much in this present age (homes, brothers, sisters, mothers, children and fields--and with them, persecutions) and in the age to come, eternal life. Mark 10:29-30 NIV
All men will hate you because of me, but he who stands firm to the end will be saved. Matthew 10:22 NIV
In the love of Christ,
Tim
... I preached on this ... 
