Knowing when to argue and when to leave it can be an art. More importantly, it requires dependence on the Holy Spirit and on wisdom from God. When we least expect it, we can be challenged on what we believe and why. In the verse above, Paul tell Titus to avoid foolish controversies. In the verse below, we see that we are to be ready to defend our beliefs, yet to do it with a sanctified heart.
"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, NASB).
We are not to get caught up in arguments that divide believers, but should use it as an opportunity to learn more about what we believe and why. Our defense of our faith (apologetics) is as important as the attitude in which we respond.