'Lack' in the Bible

What then? If some did not believe or were unfaithful [to God], their lack of belief will not nullify and make invalid the faithfulness of God and His word, will it?

That is true. They were broken off because of their unbelief, but you stand by your faith [as believers understanding the truth of Christ’s deity]. Do not be conceited, but [rather stand in great awe of God and] fear [Him];