11 Here is a trustworthy saying:
If we died with him,
we will also live with him;
12 if we endure,
we will also reign with him.
If we disown him,
he will also disown us;
13 if we are faithless,
he remains faithful,
for he cannot disown himself.
In particular, 12b and 13 confuse me. Isn't disowning someone a form of being faithless? If I disown God, am I not also being faithless? Therefore the end seems contradictory to me. Am I missing something?
In this case the answer is a bit more clear if you read from a different translation:
If we deny Him, He also will deny us;
If we are faithless, He remains faithful, for He cannot deny Himself.
Faith means "trust in God". This is the source of the confusion. In modern English, when we say "faith", it can mean "believing" in anything, but in the New Testament, this word is only used to describe a response to God. (See Vine's Dictionary)
Faithful is the verbal adjective of faith. (πιστὸς vs. πίστις). This word essentially means "having faith in God".
Faithless is equivalent to "not having faith in God", or "denying God", and is not equivalent to "denying man".
So, the passage is essentially saying:
If man denies God, God will deny man; If man denies God, God will not deny God, for God cannot deny Himself.
