On Psalm 27

(Ps 27:1) The LORD is my light and my salvation; whom shall I fear? the LORD is the strength of my life; of whom shall I be afraid?
(Ps 27:2) When the wicked, even mine enemies and my foes, came upon me to eat up my flesh, they stumbled and fell.

The verb translated "eat up" has also the figurative meaning "to destroy". Enemies can destroy the body but not the soul.

(Mt 10:28) And fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell.
(Mt 10:29) Are not two sparrows sold for a farthing? and one of them shall not fall on the ground without your Father.
(Mt 10:30) But the very hairs of your head are all numbered.
(Mt 10:31) Fear ye not therefore, ye are of more value than many sparrows.

(Ps 27:3) Though an host should encamp against me, my heart shall not fear: though war should rise against me, in this will I be confident.

(Ro 8:31) What shall we then say to these things? If God be for us, who can be against us?

(Heb 13:6) So that we may boldly say, The Lord is my helper, and I will not fear what man shall do unto me.

(Ps 27:4) One thing have I desired of the LORD, that will I seek after; that I may dwell in the house of the LORD all the days of my life, to behold the beauty of the LORD, and to enquire in his temple.
(Ps 27:5) For in the time of trouble he shall hide me in his pavilion: in the secret of his tabernacle shall he hide me; he shall set me up upon a rock.

About verse 4, though "whilst we are at home in the body, we are absent from the Lord" (2Co 5:6), a person can be part of the house of God here on earth (Heb 3:6, 1Ti 3:15). While an Old Testament believer probably did not really wish to be in the temple continually, though he certainly desired to be able to enquire in the temple,. it is clear that he desired to be part of the house of God continually. We read about it also in other passages, such as in Ps 23:6. A benefit of being part of God's house is his protection. We read about it in verse 5. This can remind us of the words of the Lord in Jn 10:29, where he stated that " ... no one is able to snatch them out of My Father's hand"EMTV.

(Ps 27:6) And now shall mine head be lifted up above mine enemies round about me: therefore will I offer in his tabernacle sacrifices of joy; I will sing, yea, I will sing praises unto the LORD.
(Ps 27:7) Hear, O LORD, when I cry with my voice: have mercy also upon me, and answer me.
(Ps 27:8) When thou saidst, Seek ye my face; my heart said unto thee, Thy face, LORD, will I seek.

If translated literally, verse 8 says "My heart said unto thee, Seek ye my face; Thy face, LORD, will I seek". Here, "Seek ye my face" is a request that the believer makes to the Lord. It follows that "ye" must refer to the Trinity. This could remind us of Jn 14:23.

(Ps 27:9) Hide not thy face far from me; put not thy servant away in anger: thou hast been my help; leave me not, neither forsake me, O God of my salvation.
(Ps 27:10) When my father and my mother forsake me, then the LORD will take me up.

Verse 10 is fulfilled in certain situations in which the parents of a believer do not serve the true God. Mt 10:35-37 would apply to this context.

(Ps 27:11) Teach me thy way, O LORD, and lead me in a plain path, because of mine enemies.
(Ps 27:12) Deliver me not over unto the will of mine enemies: for false witnesses are risen up against me, and such as breathe out cruelty.

(Mt 5:11) Blessed are ye, when men shall revile you, and persecute you, and shall say all manner of evil against you falsely, for my sake.

(Ps 27:13) I had fainted, unless I had believed to see the goodness of the LORD in the land of the living.

In verse 13, the words in italics are not required by the original text. A closer translation would be "Oh, if I had not believed to see the goodness of the LORD in the land of the living!" Thus, this verse could be applied to a person who went through difficult times and who realizes that "I do not know where would I be if I did not trust in the Lord".

(Mk 11:24) Therefore I say unto you, What things soever ye desire, when ye pray, believe that ye receive them, and ye shall have them.

(Ps 27:14) Wait on the LORD: be of good courage, and he shall strengthen thine heart: wait, I say, on the LORD.

In Ps 27:14, the words "I say" do not appear in the original text and are not required for translation. Ps 27:14 states the will of the Lord, not just an exhortation of one man to another.