Tink,
It seems like you are all over the place in the Bible-this can really drive you stir crazy when trying to absorb a bunch of 'doctrines'. Honestly, the most reliable source I have when I read the Bible is -the Spirit. Yes; commentaries can be useful and, counsel is necessary-but if it just don't pass the common sense and simple logic test-then it just might be doo doo.
I praise you for your eagerness and hunger: however, I can tell you from personal experience, that my first 2 years as a Christian (being saved) I probably did more damage than any good. You show wisdom in your inquires-and yes there are lots of different "doctrines" in the Bible. Something I had to learn to do was to 'keep my eyes on the prize'. Start any search for the truth in scripture by reminding yourself of the basics.
Our foundation is the Gospel:
Why do we need salvation?
What are we being saved from?
Who provides salvation?
How do you acquire salvation?
When is the time for salvation?
Where is the place of salvation?
If the doctrine doesn't jive with the foundation-then it probably doesn't reside on the same Rock we are on...it might just be in the 'sinking sand.'
Like Agricola said-it seems out of context. I think the author of the aforementioned paragraph threw some scripture in the blender to see what would come out. I think he was trying portray the idea of giving our spirits away to 'other gods' would be like cheating on Christ-which in essence is correct. But to use literal scripture to translate the physical to the spiritual doesn't make sense. The scripture from Mark is a physical reference whereas the scripture from II Corinthians is a spiritual reference. Follow me thus far?
Mark- is what will happen in the future physically: 14 "But when ye shall see the abomination of desolation, spoken of by Daniel the prophet, standing where it ought not, (let him that readeth understand,) then let them that be in Judaea flee to the mountains: 15 And let him that is on the housetop not go down into the house, neither enter therein, to take any thing out of his house: 16 And let him that is in the field not turn back again for to take up his garment. 17 But woe to them that are with child, and to them that give suck in those days! 18 And pray ye that your flight be not in the winter. 19 For in those days shall be affliction, such as was not from the beginning of the creation which God created unto this time, neither shall be."
II Corinthians-is the preparation of your spirit for Christ: 1"Would to God ye could bear with me a little in my folly: and indeed bear with me. 2 For I am jealous over you with godly jealousy: for I have espoused you to one husband, that I may present you as a chaste virgin to Christ. 3 But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ. 4 For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him."
I think as you grow-you will cultivate a spirit of discernment for such things; it is good that you seek-you will find. I think I can understand what the author's point is, but it is not a good mix of scripture.
TIP: when reading quoted scripture-always read AROUND- the scripture...