to kill a powerful man Gospel of Thomas Saying 98

(98) Jesus said, "What the kingdom of the father resembles is a man who wanted to assassinate a member of court. At home, he drew the dagger and stabbed it into the wall in order to know whether his hand would be firm. Next, he murdered the member of court."

Saying 98
The point of the parable is that it is necessary to prepare oneself for the inauguration of the Kingdom of God. You must become a spiritual warrior first and foremost the battle is within your own house that is your body cutting off the inclination to evil. We are victorious in Christ within our own consciousness against the enemy within and the external demons without in the world all the things that appeal to the flesh (add Gen 3; 1Jn 2:)
The certain man is the son of man, the perfect man, the man of the one, which is the multitudinous body of Christ that will kill the powerful man who is the man of lawlessness or Gog and his armies or Jesus could be the certain man who kills the powerful man who as the power of death that is the devil which is sin in the flesh. The sword is stabbed in his own house which is his body. The testing of his strength is the temping he went through to strengthen him for tribulations billeds character as Paul says:
Rom 5:3 And not only that, but we also glory in tribulations, knowing that tribulation produces perseverance; 4 and perseverance, character; and character, hope.  5 Now hope does not disappoint, because the love of God has been poured out in our hearts by the holy spirit, which was given to us. 2Co 4:17  For our light affliction, which is but for a moment, worketh for us a far more exceeding and eternal weight of glory;
Heb 12:10  For they verily for a few days chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness.
Heb 12:11  Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby.
Heb 2:18 Heb 4:15 Heb 2:9 Heb 2:14 Heb 5:7 Heb 7:23 Heb 9:15,16

98) Jesus said, "The Kingdom of the Father is like a certain man [Jesus] who wanted to kill a powerful man [ha Shatan]. In his own house [of God, where the judgment begins "For the time [is come] that judgment must begin at the house of God: and if [it] first [begin] at us, what shall the end [be] of them that obey not the gospel of God?"] he drew his sword [the Word of God "Repent; or else I will come unto thee quickly, and will fight against them with the sword of my mouth."] and stuck it into the wall [the defensive wall of church doctrine, laws and ordinances] in order to find out whether his hand [the power of the spirit] could carry through [make any headway within that religion]. Then he slew the powerful man [the spirit of anti-Christ that has controlled the "image" (in worldly churches) for 2,000 years]."