“By this we know that we love the children of God, when we love God, and keep his commandments.” 1 John 5:2
Loving God is doing what he tells us to do, not the other way round; for by this we know that we love when we keep his commandments.
His commandments are not grievous, vs 3
It isn’t hard at all, Jesus said, “For my yoke is easy, and my burden is light.” Matthew 11:30. He says, “Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls.”
“And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.” Revelation 22:17
Every child of God can or has in them that ability to obey him. “For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.” 1 John 5:4
All who believe in Jesus Christ should know in their hearts, that they are born of God and that they’re overcomers who should go forth conquering, and to conquer. “Nay, in all these things we are more than conquerors through him that loved us.” Romans 8:37
1 John 5:7-12 says,
 For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.  And there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one.  If we receive the witness of men, the witness of God is greater: for this is the witness of God which he hath testified of his Son.  He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son.  And this is the record, that God hath given to us eternal life, and this life is in his Son.  He that hath the Son hath life; and he that hath not the Son of God hath not life.
He that believeth on the Son of God hath the witness in himself: “And it is the Spirit that beareth witness, because the Spirit is truth.” (ref. vs 6). You don’t go about making God a lair but you demonstrate you have believed on the record that God gave of his Son.
Yes he has given us eternal life but you also have to agree to this, “there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one.” (1 John 5:8).
All it means is believe on the name of the Son of God, but suffer also for his sake. “For unto you it is given in the behalf of Christ, not only to believe on him, but also to suffer for his sake.” Philippians 1:29.
And these three are one – the Spirit, and the water, and the blood. Know God’s will, be sanctified, cleansed and washed by the water of of his word and strive against sin. “Ye have not yet resisted unto blood, striving against sin.” Hebrews 12:4