"Fellowship" with God is to "know" Him. To "know" God is to "keep His commandments" (1 John 2:3). This is not a "relationship" motivated by fear for "our eternal life or our eternal destruction." Rather, it is motivated by "the love of God" (1 John 2:5).
A "relationship" with God implies seeking God; and our initiating faith expressed through earnest prayer, going to worship, etc. (which are all good). But sinners do not initiate a relationship and "seek after God" (Psalm 10:4). The Good Shepherd has come "to seek and to save that which was lost" (Luke 19:10).
God in Christ has legally adopted the human family. John expresses this in the words of Jesus: "Abide in me" (John 15:4, 7). John says the brethren "abideth in Him" (1 John 2:6; cf. 2:10). The race of sinners derives temporary life by virtue of Christ's death for their sins. Each individual may chose to abide in Him and so "walk" in His life; or they may chose to opt out of the family and continue their personal alienation from God by walking outside His life.
Keeping "His word" (1 John 2:5) means believing the good news of the gospel. It is "the love of God." This is "the propitiation for our sins"; not only believers' sins, "but also for the sins of the whole world" (1 John 2:2). This gift to the world is God's love.
Jesus chose to sacrifice His life and pay the ultimate penalty; eternal death, so that no one may ever have to experience what He went through on His cross. He paid the price of eternal separation from His Father. He permanently yielded the independent use of His divinity to the Father. He died without the hope of the resurrection. All this was to win the fellowship of human hearts to God. Such love should at least evoke a heartfelt "thank you" from human lips. That is faith.
Faith sees that Jesus loves the brethren. Jesus loves "the whole world." Jesus' delight was to do the will of His Father. His whole life is a walk in His Father's commandments. Jesus said, "I am the light of the world; he that followeth me shall not walk in darkness, but shall have the light of life" (John 8:12).
John teaches that it is possible for sinners to "keep His commandments" (1 John 2:3). This is "the love of God perfected" (1 John 2:5). So John is teaching character perfection.
The question arises: How can sinners keep the commandments? As E. J. Waggoner has aptly commented: "Some people expect a great deal of humanity; God does not. It is not to be depended on, and therefore we are exhorted to become partakers of the divine nature. Human nature will always be imperfect, but the nature of God may take its place, and that is perfection." 
The answer is twofold: (1) keep "His word" (1 John 2:5); and (2) abide "in Him" (1 John 2:6).
You may chose by faith to believe the promise of "His word." All the commandments are ten gospel promises from God.
Righteousness by faith is choosing to "abide in Him." "Walk, even as He walked" (1 John 2:6). There is no life outside of Christ. He is the personal Life-giver who forgives sin and cleanses from "all unrighteousness" (1 John 1:9). Allow His life unhindered to move throughout your daily routine.
The Apostle Paul says of the heathen, that "they have their understanding darkened, being alienated from the life of God" (Eph. 4:18). Apart from His life there is darkness. The Holy Spirit moved David to say to God, "For with Thee is the fountain of life; in Thy light shall we see light" (Psalm 36:9). Since the life is the light, this is the same as saying, "In Thy life shall we see light."
How is the life of God to be obtained? The life of God is bestowed through the Holy Spirit (cf. John 7:37-39), which may be had for the asking in sincerity and faith (Luke 11:13).
--Paul E. Penno
 E. J. Waggoner, "Walking in the Light," The Present Truth 9, 30 (October 26, 1893), p. 467.