I Timothy 4:7-9, 12, 16

But reject profane and old wives’ fables, and exercise yourself toward godliness. For bodily exercise profits a little, but godliness is profitable for all things, having promise of the life that now is and of that which is to come. This is a faithful saying and worthy of all acceptance.

Let no one despise your youth, but be an example to the believers in word, in conduct, in love, in spirit, in faith, in purity.

Take heed to yourself and to the doctrine. Continue in them, for in doing this you will save both yourself and those who hear you.