I believe in the context you have stated that "mamoru" is the best choice here.
To translate your sentence "The Lord gave me protection" it would be something like this: Kamisama ga watashi wo mamotta. "The Lord protected me"

Or in Japanese script

主は、私をくばってくださいました。

I am suggesting a couple of differences to the other suggestions, partly in line with the other answers that I have given to Thomas' questions.

1) "Lord" is translated as "Shu" (literally "lord" or "master") in Christian circles. When speaking to a non-Christian then "kami" (God or Shinto Spirit) might be easier to undertand than "shu." As you might expect when speaking to someone outside the Christian tradition, the response might be "What lord or master are you refering to?" At the same time, the word "Shu" is rarely used for anything other than the Christian Lord in Japan, so if the listener were fairly educated they would understand.

BTW, "The Lord's Prayer" is translated as "Shu no inori."

2) Instead of "mamoru / mamotta" or "hogo" I have used the polite form of "kabau" (another word for protect).

2a) I used "Kabau" (instead of "mamoru") since it is used in a similar passage in Psalms.

Psalm 5:11

But let all who take refuge in you be glad; let them ever sing for joy. Spread your protection over them, that those who love your name may rejoice in you.

こうして、あなたに身を避ける者がみな喜び、とこしえまでも喜び歌いますように。あなたが彼らをかばってくださり、御名を愛する者たちがあなたを誇りますように。

(Koushite, Anatan ni mi wo sakeru mono ga minayorokobi, tokoshiemademo yorokobi utaimasu you ni. Anata ga karera wo KABATTE KUDASARI, mina wo ai suru monotachi ga anata wo hokorimasu youni. )

For my money, "Kabau" sounds more tender or loving, and from a stronger party towards a weaker party, than "mamoru", which is is more likely to be among equals.

"Hogo," the more formal, officialese word, is not used anywhere in the online bible I am referencing.


2b) I used the *polite form* - "kabatte kudasaimashita," - since it is normal to be polite about the Lord. I have used the same level of politeness as found in the bible that
I quoted in my answer to strength, but it would be possible to more polite -

Shu wa watakushi wo o kabai kudasaimashita.

But perhaps this level of politeness is not used since it sounds too distant.