OUTLINE:

“those who DO His commandments”
The Word tells us that there is a difference between those with “good understanding” and “fools” (Pr 18:2). Wisdom is understanding that obedience is good for self. Fools reject this concept.

Pr 18:1-2 [Amplified]
He who [willfully] separates himself [from God and man] seeks his own desire, He quarrels against all sound wisdom. A [closed-minded] fool does not delight in understanding, But only in revealing his personal opinions [unwittingly displaying his self-indulgence and his stupidity].

Obedience!

“by the washing of water with the word”
The Word of God has a cleansing effect. It “washes” us, sanctifying/purifying us. This is why it is so very important to receive it into our souls (e.g., read it, hear it). (cp 2Pe 1:2-3)

Heb 9:13-14 [Message]
If that animal blood and the other rituals of purification were effective in cleaning up certain matters of our religion and behavior, think how much more the blood of Christ cleans up our whole lives, inside and out.

Jn 13:10a
Jesus *said to him, “He who has bathed [he who is saved] needs only to wash his feet [with the Word]…” - Jesus

Heb 13:7 [Amplified]
Remember your leaders [for it was they] who brought you the word of God; and consider the result of their conduct [the outcome of their godly lives], and imitate their faith [their conviction that God exists and is the Creator and Ruler of all things, the Provider of eternal salvation through Christ, and imitate their reliance on God with absolute trust and confidence in His power, wisdom, and goodness].

Undistracted Devotion to the Lord
To devote oneself to the Lord’s will is to devote oneself to Him.

Undistracted Devotion to the Lord
Obedience and love exist with the same divine sphere. We cannot say that we love the Lord and yet disobey His commands (Jn 15:10). It’s a blessing among blessings to abide in this sphere!

“But in everything…”
This means that EVERYTHING in your life should pass through the divine filter/lens of the Word. As a shepherd counts his sheep under the rod, so our Great Shepherd accounts for our every word and deed (Col 3:17).

“practice [cause]…and [effect]”
Learn to maintain divine perspective (that which is gained from the Word; by reading the Bible) and the effect is that the “God of peace will be with you” (Php 4:9) and “the peace of God…will guard your hearts” (Php 4:7).

“do all things”
Paul likes to use this type of language because it reveals the pervasiveness of practical living in Christ Jesus. Col 3:17 “Whatever you do in word or deed, do all in the name of the Lord Jesus.” <— that’s how you “can do all things”!

Regarding 2Ti 2:15
You can’t “handle” something you don’t have a handle on.