Hebrews 13:9

We should reject teaching that deviates from apostolic doctrine. This, too, is a strong safeguard against apostasy. The terms "varied and strange" describe a variety of heretical positions. Rather than accepting these ideas we should receive strength by taking in God’s grace that comes through His Word (Hebrews 4:12-13; 1 Peter 2:2). This strength comes from spiritual rather than material food. Evidently one of the strange teachings prevalent when this letter originated was that certain foods or abstinence from certain foods resulted in greater godliness (cf. Colossians 2:16; 1 Timothy 4:1-5). This was, of course, what Judaism taught too. Judaism taught that eating food strengthened the heart in the sense that when the Jews ate they gave thanks to God and thus brought Him into their experience (cf. Psalms 104:14-15). [Note: Lane, Hebrews 9-13, pp. 533-36.] However, Jesus’ death on the cross is the source of both the saving and sustaining grace of God by which we experience strengthening.

"This, I think, is the key message of Hebrews: ’You can be secure while everything around you is falling apart!’" [Note: Wiersbe, 2:278.]