I agree with Perry's answer.
New International Version
"Which of the two did what his father wanted?" "The first," they answered. Jesus said to them, "Truly I tell you, the tax collectors and the prostitutes are entering the kingdom of God ahead of you.
Verb - Present Indicative Active - 3rd Person Plural
Strong's Greek 4254: From pro and ago; to lead forward; intransitively, to precede (participle, previous).
The Greek present tense indicates continued action, something that happens continually or repeatedly, or something that is in the process of happening. If you say, for instance, “The sun is rising,” you are talking about a process happening over a period of time, not an instantaneous event. The Greeks use the present tense to express this kind of continued action.
If the action of entering was happening while Jesus was speaking, then when did the Kingdom of God come?
Luke 17:20 And being asked by the Pharisees, when the kingdom of God cometh, he answered them and said, The kingdom of God cometh not with observation: 21neither shall they say, Lo, here! or, There! for lo, the kingdom of God is within you.
People have been entering the Kingdom of God ever since.