This verse appears in Greek to be the answer to two separate questions. The first phrase has no verb. The second phrase starts with a because and seems to be the response to someone asking for any explanation to the first answer. Neither answer  appears much like the KJV translation. 

The Greek word translated as "the law" describes the social norms, which can be from "tradition", "common practice," or the "laws." Christ also uses it to refer to the first five books of the OT written by Moses.

The Greek word translated as "and" is used as the conjunction "and", but it also is used to add emphasis ("also").

The Greek word translated as "the prophets" means "one who speaks for God", "interpreter" and was the highest level of priesthood in Egypt. Christ uses it to refer not only to divine spokespeople but their books in the OT. It is the verb that means "to shine before." Our word "luminaries" captures the idea very well. 

There is no "were" here. It is assumed because the phrase contains a subject but no verb. This makes the phrase seem to be the answer to a question. 

The Greek word translated as "until" means "up to," and "until." This is a rare proposition for Jesus to use. 

"John" is the Greek word translated as the English proper name. 

The word translated as "since" means "from" in both location and when referring to a source.

The Greek word for "that time" means "at this time" or "then". 

The word translated as "the kingdom" can be the region, the reign, the castle or the authority of a ruler. Christ does not seem to use it to mean a physical region, so its translation as "reign" or "realm" seems more appropriate. This is especially true because the "reign" of a king means the execution of his will.

The word translated as "God" means "God" and "deity." It is introduced with an article, so "the God." Christ often uses it this way perhaps to indicate the one God as opposed to the pagan gods.

"Is preached" is translated from a Greek verb that means to"bring good news," and, in the passive, "receive good news." It is only translated as "preach" in the Gospels, but the concept of "preaching" didn't exist at the time. It is not a passive as translated, but in a form which indicates the subject acting for or by itself. It is in the form of "brings by itself good news".  The realm of God is the subject.

The Greek word translated as "and" is used as the conjunction "and", but it also is used to add emphasis ("also"). In a series, is best translated as "not only...but also." After words implying sameness "as".

The word translated as "every man" is the Greek adjective meaning "all", "the whole", "every," and similar ideas. When it is used as a noun, we would say "everything" or "everyone".  This "all" or "everyone" is followed by the qualifying phrase "in it" referring to the realm

"Presseth" is a verb that means "to constrain", "to force," and "to use violence." This verb is translated as "suffereth violence" in Matthew 11:12.  The form in both verses is the same, not an active form, like here, nor a passive form, like the Matthew version. It is a form where the subject acts on itself as with the earlier verb. The sense is, "constrains himself". 

The phrase "into it" appears after the "all" and before the verb. It could refer to the place constrained, but that seems less likely because the verb acts on the subject. More likely, this phrase refers to the "all". 

The word translated as "into" means "into" a place, "towards" as a direction, "in regards to" a subject, and "up to" limits in time and measure.

The word translated as "it" is the Greek word commonly translated as pronouns in English. The form of the word refers back to "realm".