Matthew 11:12

And from the days of John the Baptist until now the kingdom of heaven suffereth violence, and the violent take it by force.

"[And from the days of John ...] That is, from the days when John began to preach. It is not known how long this was, but it was not probably more than a year. Our Saviour here simply states a fact. He says there was a great rush or a crowd pressing to hear John. Multitudes went out to hear him, as if they were about to take the kingdom of heaven by force. See <Matt. 3:5>. So, he says, it has continued. Since "the kingdom of heaven," or "the gospel," has been preached, there has been a "rush" to it. People have been "earnest" about it; they have come "pressing" to obtain the blessing, as if they would take it by violence. There is allusion here to the manner in which cities were taken. Besiegers "pressed" upon them with violence and demolished the walls. With such "earnestness" and "violence," he says, people had pressed around him and John since they began to preach. There is no allusion here to the manner in which individual sinners seek salvation, but it is a simple record of the fact that multitudes had thronged around him and John to hear the gospel."

(from Barnes' Notes)

Here in this verse, Jesus is stating a fact. The "multitudes" and "throngs" of people came out both to John as well as Jesus, "crowding" and "pressing" them with "their strength" as though in this manner they might have entrance into the kingdom. This was probably due to the heavy burdens of the Scribes and Pharisees which caused the multitudes to "energetically" seek another way (Mtt 23:1-4, 13). Jesus is not saying that this is the "way," or the "manner" into the kingdom, but that this was the manner in which the multitudes were approaching. Of course, Jesus presents Himself in the Cross to be the only Way (Jn 3:1-5, 13-15; Jn 14:5-6). It is not a "how" nor by a "doing," but by a "Whom" (Christ Crucified) that entrance is given into the kingdom. As soon as this begins to be understood, the multitudes soon leave, clearly seeing that it is "Not by might, nor by power, but by my spirit, saith the LORD of hosts" (Zec 4:6; Mrk 10:17-27; Jn 6:40, 44; Jn 6:54; Jn 6:60-66).

(from C.M.I. Bible Research Center)

References:

Mtt 23:1-4

Then spake Jesus to the multitude, and to his disciples, Saying, The scribes and the Pharisees sit in Moses’ seat: All therefore whatsoever they bid you observe, [that] observe and do; but do not ye after their works: for they say, and do not. For they bind heavy burdens and grievous to be borne, and lay [them] on men’s shoulders; but they [themselves] will not move them with one of their fingers.

Mtt 23:13

But woe unto you, scribes and Pharisees, hypocrites! for ye shut up the kingdom of heaven against men: for ye neither go in [yourselves], neither suffer ye them that are entering to go in.

Jn 3:1-5

There was a man of the Pharisees, named Nicodemus, a ruler of the Jews: The same came to Jesus by night, and said unto him, Rabbi, we know that thou art a teacher come from God: for no man can do these miracles that thou doest, except God be with him. Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God. Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother’s womb, and be born? Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and [of] the Spirit, he cannot enter into the kingdom of God.

Jn 3:13-15

And no man hath ascended up to heaven, but he that came down from heaven, [even] the Son of man which is in heaven. And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: That whosoever believeth in him should not perish, but have eternal life.

Jn 14:5-6

Thomas saith unto him, Lord, we know not whither thou goest; and how can we know the way? Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.

Zec 4:6

Then he answered and spake unto me, saying, This [is] the word of the LORD unto Zerubbabel, saying, Not by might, nor by power, but by my spirit, saith the LORD of hosts.

Mrk 10:17-27

And when he was gone forth into the way, there came one running, and kneeled to him, and asked him, Good Master, what shall I do that I may inherit eternal life? And Jesus said unto him, Why callest thou me good? [there is] none good but one, [that is], God. Thou knowest the commandments, Do not commit adultery, Do not kill, Do not steal, Do not bear false witness, Defraud not, Honour thy father and mother. And he answered and said unto him, Master, all these have I observed from my youth. Then Jesus beholding him loved him, and said unto him, One thing thou lackest: go thy way, sell whatsoever thou hast, and give to the poor, and thou shalt have treasure in heaven: and come, take up the cross, and follow me. And he was sad at that saying, and went away grieved: for he had great possessions. And Jesus looked round about, and saith unto his disciples, How hardly shall they that have riches enter into the kingdom of God! And the disciples were astonished at his words. But Jesus answereth again, and saith unto them, Children, how hard is it for them that trust in riches to enter into the kingdom of God! It is easier for a camel to go through the eye of a needle, than for a rich man to enter into the kingdom of God. And they were astonished out of measure, saying among themselves, Who then can be saved? And Jesus looking upon them saith, With men [it is] impossible, but not with God: for with God all things are possible.

Jn 6:40, 44

And this is the will of him that sent me, that every one which seeth the Son, and believeth on him, may have everlasting life: and I will raise him up at the last day…. No man can come to me, except the Father which hath sent me draw him: and I will raise him up at the last day.

Jn 6:54

Whoso eateth my flesh, and drinketh my blood, hath eternal life; and I will raise him up at the last day.

Jn 6:60-66

Many therefore of his disciples, when they had heard [this], said, This is an hard saying; who can hear it? When Jesus knew in himself that his disciples murmured at it, he said unto them, Doth this offend you? [What] and if ye shall see the Son of man ascend up where he was before? It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, [they] are spirit, and [they] are life. But there are some of you that believe not. For Jesus knew from the beginning who they were that believed not, and who should betray him. And he said, Therefore said I unto you, that no man can come unto me, except it were given unto him of my Father. From that [time] many of his disciples went back, and walked no more with him.