Jhn 8:42 If God were your Father, ye would love me: for I proceeded forth and came from God; neither came I of myself, but he sent me.
If God was a parent of yours, you might welcome me since I set forth and have come out from God. For I never set out for myself since, after all, he sent me.
Reading this verse in English, you would naturally think that the verbs in the phrases "came from God" and "came I for myself" were the same verb in Greek. They are not. This makes this verse is a great illustration of why the Greek word usually translated as "come" in the NT (as in Mat 6:10 Your kingdom come...), erchomai, doesn't really work when translated that way.
Here, we see Christ using the word that really does consistently mean "to come," (heko, the verb in the "came from God" phrase) with not one, but two different versions of erchomai, the verb used in the "came I for myself" phrase". The difference is important to understanding not only this verb but many verses of Christ's words better.
Though the primary meaning of erchomai is "started", Christ doesn't often use it in the sense of "to begin." He uses it to mean making progress or movement without reference point to direction, at least in the verb. What is does a "reference point to direction" mean? We use the verb "come" in English to imply movement toward our current point. We use the verb "go", at least usually, to imply movement away from our current point. Erchomai can be translated as either as long as we don't infer a reference point. In English, we say,"He is on his way" to capture the idea of movement without a reference point. Someone could be "on his way here" or "on his way there" but if we just say "on his way", we mean only that he is in transit.
The KJV almost always translates erchomai as "come" because they want to believe that the type of movement that it refers to is toward us. For example, in the "Your kingdom come" verse," they wanted to believe that the movement of God's kingdom is toward us. However, that is not what Christ is saying. He is saying that God's kingdom is moving forward only. The rest may be our desire but it is not Christ's promise.
This verse offers a good example of how the usual "come" translation for erchomai can fail. In the phrase translated as "proceeded forth," Christ uses the verb exerchomai, which is erchomai preceeded by the preposition, ek. The preposition gives exerchomai an implicit direction since the word means "out" or "from." However, the verb is used withthe Greek word that must be translated as "come," heko AND the proposition ek introducing a phrase "ek o theos" "from God." Translating this as "I came from and came from God" is redundant. So the KVJ version used "proceeded forth" which captures the idea of erchomai much better than their usually "come."
Εἰ "If" is from ei, which is the particle used to express conditions "if" (implying nothing about its fulfillment) or indirect questions, "whether." It also means "if ever", "in case," and "whenever." It is combined with various conjunctions to create derivative conditions.
ἠγαπᾶτε (2nd pl imperf ind act) "Ye...love" is from agapaô (agapao), which means "to be fond of", "to greet with affection", "to persuade", "to caress", "to prize", "to desire", "to be pleased with," and "to be contended with." This love is more associated with affection than passion.
ἂν "Would" is from an, which is a particle used with verbs to indicate that the action is limited by circumstances or defined by conditions. There is no exact equivalent in English, but it is translated as "would have", "might", "should," and "could."
ἐκ "From" is from ek, which means 1) [of motion] "out of", "from", "by", "away from;" 2) [of place] "beyond", "outside of", "beyond;" 3) [of succession] "after", "from;" 4) [of rest] "on", "in," 5) [of time] "since", "from", "at", "in;" 5) [of materials] "out of", "made from."
ἐξῆλθον (1st sg aor ind act) "Proceeded forth" is from exerchomai (exerchomai), which means "to come or go out of " "to march forth", "go out on", "to stand forth", "to exceed all bounds", "to come to an end", "to go out of office," and [of dreams or prophecies] "to come true."
καὶ "And" is from kai, which is the conjunction joining phrases and clauses, "and," or "but." After words implying sameness, "as" (the same opinion as you). Used in series, joins positive with negative "Not only...but also." Also used to give emphasis, "even", "also," and "just."
ἐλήλυθα 1st sg perf ind act "Came I" is from erchomai (erchomai), which means "to start," "to set out", "to come", "to go," and any kind of motion. It means both "to go" on a journey and "to arrive" at a place.
"Me" is from eme, which means "I", "me", and "my".