"For this is the love of יהוה [Yahweh, our god], that we keep his commandments: and his commandments are not grievous." 1 John 5:3
Notice, this is exactly what Solomon said, as the whole duty of man.
But, which title is correct? "Keep HIS Commandments" (or) "KEEP his Commandments"? Notice that the words are the same. The emphasis is different. The emphasis depends on the interpretation (understanding) of the reader. But, which is correct? Is there a difference?
KEEP his Commandments
This is the usual interpretation, meaning obey. Put simply, it is wrong.
"For all have sinned, and come short of the glory of יהוה [Yahweh, our god];" Romans 3:23
If ALL have sinned, then NONE have kept (obeyed) his commandments, making Ecclesiastes 12:13 an impossibility and this interpretation obviously wrong.
"And he said unto him, Why callest thou me good? there is none good but one, that is, Elohim [god]: but if thou wilt enter into life, keep the commandments." Matthew 19:17
Besides, this interpretation requires good works. No one will go to Heaven because of their works, but by having the faith of Yahweh. (See Faith or Works also Salvation By Faith)
Let's look at the alternative interpretation:
Keep HIS Commandments
This statement completely and accurately defines the great controversy between good and evil, Yahweh and Satan and is the heart of the gospel (see Everlasting Gospel). Satan has rebelled and wishes to overthrow Yahweh's government, replacing it with his own.
"I [Satan] will ascend above the heights of the clouds; I will be like the most High." Isaiah 14:14
"Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?" Romans 6:16
Speak unto the children of Israel, and say unto them, I am יהוה your Elohim. After the doings of the land of Egypt, wherein ye dwelt, shall ye not do: and after the doings of the land of Canaan, whither I bring you, shall ye not do: neither shall ye walk in their ordinances. Ye shall do my judgments, and keep mine ordinances, to walk therein: I am יהוה your Elohim. Ye shall therefore keep my statutes, and my judgments: which if a man do, he shall live in them: I am יהוה. Leviticus 18:2-5
The question is NOT "how well you obey?" (because we ALL are imperfect) but "WHO you choose to obey? (even if imperfectly)"
The question is not how perfectly you obey God's commandments, but Who's commandments you choose to follow.