7 Bible Verses about Being Assertive

But speaking the truth in love [in all things—both our speech and our lives expressing His truth], let us grow up in all things into Him [following His example] who is the Head—Christ.

“You have heard that it was said, ‘An eye for an eye, and a tooth for a tooth [punishment that fits the offense].’ But I say to you, do not resist an evil person [who insults you or violates your rights]; but whoever slaps you on the right cheek, turn the other toward him also [simply ignore insignificant insults or trivial losses and do not bother to retaliate—maintain your dignity, your self-respect, your poise]. If anyone wants to sue you and take your shirt, let him have your coat also [for the Lord repays the offender]. read more.
And whoever forces you to go one mile, go with him two. Give to him who asks of you, and do not turn away from him who wants to borrow from you.

And [His gifts to the church were varied and] He Himself appointed some as apostles [special messengers, representatives], some as prophets [who speak a new message from God to the people], some as evangelists [who spread the good news of salvation], and some as pastors and teachers [to shepherd and guide and instruct], [and He did this] to fully equip and perfect the saints (God’s people) for works of service, to build up the body of Christ [the church];

Since we have such a [glorious] hope and confident expectation, we speak with great courage,

Be angry [at sin—at immorality, at injustice, at ungodly behavior], yet do not sin; do not let your anger [cause you shame, nor allow it to] last until the sun goes down. And do not give the devil an opportunity [to lead you into sin by holding a grudge, or nurturing anger, or harboring resentment, or cultivating bitterness].

The weapons of our warfare are not physical [weapons of flesh and blood]. Our weapons are divinely powerful for the destruction of fortresses. We are destroying sophisticated arguments and every exalted and proud thing that sets itself up against the [true] knowledge of God, and we are taking every thought and purpose captive to the obedience of Christ,

Now the serpent was more crafty (subtle, skilled in deceit) than any living creature of the field which the Lord God had made. And the serpent (Satan) said to the woman, “Can it really be that God has said, ‘You shall not eat from any tree of the garden’?” And the woman said to the serpent, “We may eat fruit from the trees of the garden, except the fruit from the tree which is in the middle of the garden. God said, ‘You shall not eat from it nor touch it, otherwise you will die.’” read more.
But the serpent said to the woman, “You certainly will not die! For God knows that on the day you eat from it your eyes will be opened [that is, you will have greater awareness], and you will be like God, knowing [the difference between] good and evil.” And when the woman saw that the tree was good for food, and that it was delightful to look at, and a tree to be desired in order to make one wise and insightful, she took some of its fruit and ate it; and she also gave some to her husband with her, and he ate.