Fellowship is an important Bible doctrine and has serious ramifications for our practice as God's children. Fellowship is the state, condition or quality of persons being companions, partners, or sharers together in some action, benefit, or relation which is common to all the participants.
To have joint participation with someone, in and of itself, does not prove anything as to the rightness or endorsement of that participation. Two men may be at opposite ends of an issue and "jointly participate" in debating their differences. It does not mean they are "in fellowship" with one another for there is certainly no joint approval nor acceptance of each other. The fellowship we need to focus on is a working together, mutual acceptance, and approval - a harmony and unity as we serve God.
Christians need to be careful what they show that they are in fellowship with. My posts or "likes" on social media may show that I "approve" of immodest dress (cheerleading outfits or swimsuits), drinking (holding beer or alcoholic beverages), dancing (posting Prom and other dance pictures), gambling (selling raffle tickets or bingo), or unscriptural situations (like adulterous marriages or children born out of wedlock). Now I may not believe that any of these are righteous activities, but how will anyone know as they look on their phone or tablet? But I can't put all the burden on social media. Christians show their "approval" of these aforementioned sins in many ways other than just online. One of the reasons why being a Christian is difficult is because we always have to take heed that we are being "lights in the world" (Philippians 2:15).
Regarding our fellowship, Paul sternly warned, "For ye were sometimes darkness, but now are ye light in the Lord: walk as children of light: (For the fruit of the Spirit is in all goodness and righteousness and truth;) Proving what is acceptable unto the Lord. And have no fellowship with the unfruitful works of darkness, but rather reprove them" (Ephesians 5:8-11). David, the man after God's heart, said, "Through thy precepts I get understanding: therefore I hate every false way" (Psalm 119:104; cp. v. 128). If we think it is important to be like Christ (and it is, Romans 8:29), then Hebrews 1:9 says, "Thou hast loved righteousness, and hated iniquity; therefore God, even thy God, hath anointed thee with the oil of gladness above thy fellows." You need to really think - do your daily actions show that you hate everything that is false and wicked? We are under direct command of God and the example of Christ Himself to "come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing" (2 Corinthians 6:17).
Someone might counter that Jesus ate with sinners, therefore we can be in the general company of and show our agreement with people in sin. Yes, Jesus did eat with them (Matthew 9:13; Mark 2:17; Luke 5:32), but He did so to "call... sinners to repentance." He did not do it to primarily be their friend, but to present Himself as the Great Physician, teaching and admonishing them to change their lives. Weak Christians make no effort to teach - they just "agree" and "approve" by virtue of what they publicly and privately convey. These Christians need teaching and growth (Colossians 1:9-11; 1 Peter 2:2). Hebrews 5:14 declares that the mature are "those who by reason of use have their senses exercised to discern both good and evil." They understand the consequences of what they communicate publicly and privately.
On the other hand, it is good to see strong, conscientious brethren who demonstrate their fellowship with righteousness by "liking" scriptural quotes and godly articles on various Bible topics. Furthermore, they express spiritual, virtuous thoughts to both saints and sinners. Such people ensure that the Lord's church will be strong and faithful in the years to come. May their tribe increase!
- The Gospel Teacher, 5/6/18