Most important is that you share the Good News (Gospel). This is simple. All these other things may help, but it is the proclamation of the Gospel that transforms minds. See Give Them the Gospel. It's pretty simple really.

1. The ungodly already know that God exists and that He is a just God Who must judge them for their refusal to acknowledge Him.
2. When they say that they don't believe in God, they are not telling the truth.  They know God exists.
3. The real motivation for the ungodly evangelist is that they are slaves to Satan who hates God.
4. Every Christ-follower hears God's Voice and a real ongoing experience.  This is not an assumption, worldview, or presupposition.  It is an ongoing experience.  It is empirical.
5. They don't use facts or science.  They use emotion, poor logic, lies, exaggerations, name-calling, and every form of ridicule and rudeness.
6. Evolution, Big Bang, Old Earthism, Naturalism, Materialism, and Uniformitarianism are all just fairy tales.  There is no evidence that any of these are true stories and they have huge conflicts with real science.  They are claimed to be true and proven, but they are not.
7. Their logic is always faulty, but it falls on it's foundational premise in every case.
8. Every foundational premise they use is simply an unsupported assertion.  The ungodly person cannot defend this assertion except by becoming irrational.
9. Those foundational premises are almost always the following:
10. God does not exist.
    1. There is no spiritual realm. (Note: Hindu, Buddhism, Eastern, New Age, and Christ Science are some of the religions that teach that there is a spiritual realm only and no physical realm. Naturalism, Athiesm, and Materialism are some of the religions that teach that there is a physical realm only and no spiritual realm. Christianity, Jewism, and Islam are some of the religions that teach that there is both a physical and spiritual realm.)
    2. The flood never happened.
    3. Creation never happened.
    4. There is no coming judgment.

And there is no basis in fact for any of these statements.  At best, they are arbitrary assumptions.  At worst, they are nasty lies that are being told as lies on purpose.

Example of what ungodly people sometimes say:

"There is no choice. We have the natural world we live in and that’s it."

This is a statement of make-believe faith in the dogma of Naturalism.  This irrational belief says that the natural world is all that there is.  Stating it this way mixes Naturalism with the dogma of Materialism.  Materialism states that there is only a material world.  There is no spiritual realm and there are no spiritual entities.  Of course, hidden in all of this is the obvious implication that there is no God.  Naturalism is the belief that everything is caused by natural causes.  Natural is defined as that that is not caused by any spiritual cause.  Saying, “and that’s it” implies that there is no God and no heaven and no hell.  Also, implied in this rather short two-sentence claim is the claim that God doesn’t speak to anyone anywhere throughout all time.

This is known in logic as a universal negative.  It is a classic irrational statement—a statement that violates logical reason.  In essence, it is an insane statement.  The person is claiming to be omniscient, to understand every person’s experience throughout time and to be able to know about everything that is happening in every part of the universe whether spiritual or material.  Jesus Christ can make claims that involve being all-knowing.  He knows everything.  He holds everything together throughout the entire universe both spiritual and material.

If you ask a person who makes such a statement how he or she knows such a thing, they cannot answer.  They just know.  But how?  Perhaps they are claiming to know all things.  More likely, they heard someone else say such a foolish thing and they had already turned their backs on God and those things sounded good to them, so they believed this other foolish person rather than believing God.

Rule 1:  Physical nature, matter, and energy is all that exists (Naturalism and Materialism).
Rule 2: See rule 1.

What do you say if they reject Christ and just want to argue?