Hello Shelby!
Peace be with you :-)
The Greek verb "to search" is rendered in the active voice and indicative mood of the present tense in verse 39.
I think that maybe the problem with the Authorised Version (KJV) at John 5 v 39 is that the subject of the sentence is omitted. It should read:
"Ye search the scriptures...." rather than simply, "Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me. "
This has been rectified in the New King James Version which has "You search the Scriptures, for in them you think you have eternal life; and these are they which testify of Me."
For the word "search"... just "search"... is FUTURE tense! It means TO search... to do something in the FUTURE.
There appears to be some confusion here as "search" is in fact present; "will/etc search" is future (the use of the modal verb 3rd singular present 'will' expressing the future tense of "search" here); and "to search" is the infinitive form of the verb. The omission of the subject "Ye", i.e. "you the Jews" (referring back to earlier verses in chapter 5) may cause some to misunderstand and to interpret "search the scriptures" as a command, either for now or for the future.
[As a point of interest, in the majority of instances the present tense in Greek corresponds directly with the English present tense. However, sometimes the present tense is used in Greek for phrases where we would use the past tense in English. These "historical presents" "dramatize" the event for the reader. "Historical presents" are rendered in some translations in the past tense in English, whilst others keep to the present tense.]
Shelby, do you have the NWT version of verse 39 which you could post for me please? I'd be interested to know what it says. If not, no problem :-)
I bid you peace!