How about we must live by the commandments of Jesus yet we teach from Doctrines of men. With our mouths we prays and honour the Lord but our hearts are far away.
Isaiah 29:9-14 Matthew 15:8-9 Mark 7:6-9 John 15:10
Rom 11:16 For if the firstfruit [be] holy, the lump [is] also [holy]: and if the root [be] holy, so [are] the branches.
1Cr 3:17 If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which [temple] ye are.
2Cr 13:12 Greet one another with an holy kiss.
Eph 1:4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
Col 1:22 In the body of his flesh through death, to present you holy and unblameable and unreproveable in his sight:
1Th 5:27 I charge you by the Lord that this epistle be read unto all the holy brethren.
1Ti 2:8 I will therefore that men pray every where, lifting up holy hands, without wrath and doubting.
2Ti 1:9 Who hath saved us, and called [us] with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began,
Tts 1:8 But a lover of hospitality, a lover of good men, sober, just, holy, temperate;
Hbr 3:1 Wherefore, holy brethren, partakers of the heavenly calling, consider the Apostle and High Priest of our profession, Christ Jesus;
Okay cool, I was considering something outside of what Jesus taught and did not mince words about. Which re-affirms what I have always maintained, that most people don't consider. The 1st 4 books of the NT are what constitute the Gospel. Outside Acts and Revelations, the the remaining are the letters of the Apostles and our guide to effective witnessing. Witnessing is simply explaining how your life is different (better) with Jesus in it.
The doctrine of Godliness as Paul called it, he was a good witness to Jesus, is a very direct and specific teaching of Jesus. That is why he called it a doctrine. It was in Matthew 5:19-20, interestingly enough the heading for that group from Matt 5:15-20 is, "Teaching About the Law", and likely in the other 3 in a similar way.