For  -- The word translated as "for" introduces a reason or explanation so "because" and, in questions, "why". However, since this word always appears in the second position, it is more like an aside remark like, "consequently" or "as a cause". 

I -- This is from the first-person, singular form of the verb. 

missing "myself" -- (MW)  The pronoun "I" is used here.  When the subject of the sentence is part of the verb, this pronoun accentuates who is speaking "I". Saying "I myself" captures this feeling in English. The subject pronoun repeats the information in the verb so it should be repeated in English like "I myself". When it has no verb, the verb "is" or the previous verb is assumed. 

will -- This helping verb "will" indicates the verb is in the future tense. Helping or auxiliary verbs are needed to translate the Greek verb forms into English. - However, the verb could also be in the form of possibility, "might".

give -- The verb translated as "give" means "to give", "to grant", "to hand over", "appoint", "establish" and "to describe". It is almost always translated as some form of "give".

you -- The Greek pronoun "you" here is plural and in the form of an indirect object, "to you", "for you", etc. 

a -- There is no indefinite article in Greek, but when a noun doesn't have a definite article, the indefinite article can be added in English translation.

mouth -- The Greek word translated as "mouth" is  means "mouth" and therefore, "speech" or "utterance". The Greek use this word to mean speech in the sense we say "that kid has a mouth on him" or describe being outspoken as "mouthing off". The sense is often humorous and deprecating since everyone has a mouth.

and -- The Greek word translated as "and" is used as the conjunction "and", but it also is used to add emphasis ("also"). "Also" may work best here because wisdom is what is highlighted in the rest of the verse.

wisdom-- Wisdom" is a word meaning "cleverness", "skill", "learning" and "wisdom". The Greek word, Sophia, was the goddess of wisdom among the Greeks. Among the Jews, this attribute was first recognized as an attribute of God and was later identified with the Spirit of God. In Greek, however, the word carried not just the idea of superior knowledge, but superior skill in doing things in the real world. It was a practical knowledge, more like we use the word "common sense". This serious idea is contrasted with the "mouth" above. Wisdom is what is discussed from now on.

which -- The word translated as "which" is a demonstrative pronoun ("this", "that"), but it often acts as a pronoun ("the one that"), especially a connective pronoun ("the one that") introducing a dependent clause. The form refers only to the "wisdom" not the "mouth".

all -- -- (OS) This is not the word in the source we use today but it does exist in the source that the KJV translators used.  Today, the term translated as "all" includes several senses of "everything" and completeness. It is more extreme than the common word for "all". 

your -- (WF) The Greek pronoun "your" here is plural and in the form of an indirect object, "to you", "for you", etc.  This is not a possessive but an indirect object.

missing "the/this"  -- (MW) The untranslated word is the Greek definite article, "the", which usually precedes a noun or changes the word it precedes (adjective, infinitive, participle, etc.) to act like a noun. The Greek article is much closer to our demonstrative pronouns ("this", "that", "these" and "those"). See this article for more. 

adversaries --"Adversaries" is from a verb beginning with "anti" which is used uniquely here. It means to "set against", "match with", in battle "withstand", "compare",  "resist" and "fight on". This word is at the end of the sentence, either to create suspense or to act as a punchline.

shall -- This helping verb "shall" indicates the verb is in the future tense. Helping or auxiliary verbs are needed to translate the Greek verb forms into English.

not -- The Greek word translated as "not" is the Greek negative used to deny objective facts, not opinions. It makes a negative statement of fact. Adding "really" to the sentence captures the same idea.

be -- This verb is not a passive voice but a middle voice requiring some form of "self" as the object. 

able -- The word translated as "able" means having the power or possibly a desire to accomplish something. Often, in English, "can" is a helper verb, indicating a possibility. In Greek, it indicates ability or power. This is the active verb here, not a helper verb. It takes an infinitive as "have the ability" does in English. 

to -- This "to" is added to create the infinitive form of the following verb.

gainsay -- "Gainsay" is another unique "anti" verb that means to "speak against", "speak in answer", "contradict" and "deny".

nor -- "Nor" is translated from a Greek word that means primarily "or" but serves as "than" in a comparison.

resist  -- "Resist" means "to set against", "to match with", "to compare", "to stand against", "to withstand", "to turn out unfavorably" and "to make a stand".