1. Brothers and fathers, hear my defense which I now offer to you (Acts 22:1).

The Apostle Paul is offering a defense to certain things he was wrongly accused of.

2. And I answered them that it is not the custom of the Romans to hand over any man before the accused meets his accusers face to face, and has an opportunity to make his defense against the charges (Acts 25:16).

Here the word is used in the technical sense of making a defense against accusers.

3. My defense to those who examine me is this (1 Corinthians 9:3).

Paul again is using the term in the legal sense.

4. For behold what earnestness this very thing, this godly sorrow, has produced in you: what vindication of yourselves, what indignation, what fear, what longing, what zeal, what avenging of wrong! In everything you demonstrated yourselves to be innocent in the matter (2 Corinthians 7:11).

Here the word has the idea of vindication.

5. For it is only right for me to feel this way about you all, because I have you in my heart, since both in my imprisonment and in the defense and confirmation of the gospel, you all are partakers of grace with me (Philippians 1:7).

The scope of Paul's ministry concerns both the defense and confirmation of the good news. This implies that his response or apology was closely linked with the gospel.

6. The latter do it out of love, knowing that I am appointed for the defense of the gospel (Philippians 1:16).

This clearly points out his purpose - he is set for the defense of the gospel.

7. At my first defense no one defended me, but all deserted me; may it not be counted against them (2 Timothy 4:16).

This could mean defend or support in front of hostile witnesses.

8. but sanctify Christ as Lord in your hearts, always being ready to make a defense to everyone who asks you to give an account for the hope that is in you, yet with gentleness and reverence (1 Peter 3:15).

This is a key verse with respect to the defense of the Christian faith. Here it is in the context of persecution. When asked, we are commanded to have an answer as to what we believe and why we believe.