In John 13:35, Jesus says, "By this all people will know that you are my disciples, if you have love for one another."
This kind of love is not merely a warm, affectionate feeling toward another. After all, it's something others can see and recognize. However, it isn't deliberately attention-getting either.
In John 12:43, Jesus warned His disciples about the Pharisees' motives. "For they loved the glory that comes from man more than the glory that comes from God."
The ability to love one another in a Christlike way comes from the Holy Spirit. This kind of love is affection that is selflessly lived out before others.
Jesus loved us and that motivated Him to give His life for us on the cross. This selfless kind of love, a love that puts others ahead of oneself, stands out in a self-centered culture. When we love this way, others will wonder how it's possible. And, hopefully, they will come to recognize us as Christians who live out the gospel.
Sadly, too many churches are known for their squabbles and divisions. And often these divisions aren't over foundational theological differences. Instead, they're about personal preferences. Founding members resist change. New members want to be heard. And on it goes. But it isn't our church. It's God's. And He says we'll be known by our love. We must keep this in mind.
In the 70s, there were many who thought segregation was the answer. White churches. Black churches. Rich churches. Poor churches. Rural churches. Urban churches. They thought that would stop the fighting.
But this wasn't—and isn't—God's plan. We're meant to be a family with members from many different backgrounds. Galatians 3:23 says, "There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus."
There are some churches who say they believe this but still have two services, a traditional service primarily for an older demographic and a contemporary service geared toward young people and millennials. That's still division. The older generation needs the freshness of youth, and the youth need the wisdom and stability of the older generation.
Tertullian, an early church father who lived between 160-225 AD, wrote about what unbelievers said about Christians loving one another. "The heathens said of believers, 'Behold, how these Christians love one another! ... They love one another before they get to know one another."
As Christians, we must evaluate ourselves as to whether or not we're displaying Christlike love for one another, not just for fellow believers we easily relate to, those who share our opinions and outlook.
Part of loving is listening, really listening. It's too easy to fixate on something that we can't truly hear what the other person is saying.
John 13:36-38 says, "Simon Peter said to him, 'Lord, where are you going?' Jesus answered him, 'Where I am going you cannot follow me now, but you will follow afterward.' Peter said to him, 'Lord, why can I not follow you now? I will lay down my life for you.' Jesus answered, 'Will you lay down your life for me? Truly, truly, I say to you, the rooster will not crow till you have denied me three times.'"
Peter was with Jesus from the beginning of His ministry. He witnessed the miracles. He heard the teaching. And yet, when Jesus said He was going somewhere Peter couldn't go, he was adamant that His Master must be wrong.
Peter didn't understand that Jesus was talking about heaven. He still expected Him to establish an earthly kingdom. And no matter how dangerous it would be, Peter wanted to assure Jesus of His loyalty and commitment.
Elmer Towns points out an observation worth noting. According to Mark, Peter later argued, "Even though they all fall away, I will not." 
Peter thought that he was fully committed to Jesus, and in many ways, he was. But his failure came from not recognizing his own weakness. He trusted in his own abilities, his own power, his own resolve, all of which set him up for colossal failure. And Peter wasn't the only disciple who didn't understand what Jesus had come to accomplish or how He would accomplish it.
Still, Jesus didn't abandon His disciples. Think about that for a minute. Jesus knew Peter would deny Him three times. He knew the disciples would desert Him and run away after He was arrested, even though they all protested they would never do such a thing (Matthew 26:31, 35, 56). He knew Thomas would doubt the resurrection. But Jesus didn't send them away. He didn't reject them. Instead, He loved them to the end. And, after His resurrection, He sent them out to spread the gospel.
If we are to love as Christ loved us, that means we're committed to the other person's highest good. And the highest good for all people is for them to become more like Jesus by growing in holiness and living their lives to glorify Him. In fact, one way we can see that type of commitment is in marriage.
Paul says in Ephesians 5:25-27, "Husbands, love your wives, as Christ loved the church and gave himself up for her, that he might sanctify her, having cleansed her by the washing of water with the word, so that he might present the church to himself in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish."
This kind of selfless love helps a wife grow in her faith and become more Christlike. Selfless love for one another in the church will help us all become more like Jesus.
By examining Jesus, we can see what biblical love looks like. It's self-sacrificing, caring, and seeks the highest good for others. We must be willing to put others first. We must genuinely care for them. Our love must go beyond feelings. It must be active.
But how can we live this way? How can we love this way? Are there enough hours in our schedule?
Even Jesus spent more time with three of His disciples: Peter, James, and John. Does that mean He didn't love the others as much? That He didn't value them as highly? Of course not.
Plus, Jesus loved His enemies, those who sought to kill Him. But He didn't go out of His way to spend time teaching them personally like He did with His disciples.
We don't only show love to others by spending time with them. It's crucial that we pray for those the Lord has brought into our life—and for ourselves. If we're not praying for God to give us wisdom and the ability to obey His command to love … If we're not asking for discernment as to how to display that love … Then, we can't effectively love one another as Christ loved us.
If we try, in our own strength, to love others as God commands, we'll end up frustrated, defeated, resentful, and quite possibly hurting the ones we're seeking to love.
We must meditate on the characteristics of biblical love as found in 1 Corinthians 13: "Love is patient and kind; love does not envy or boast; it is not arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice at wrongdoing, but rejoices with the truth. Love bears all things, believes all things, hopes all things, endures all things."
Loving like Jesus loves is a lifelong endeavor. Seeing the unity among believers that our Savior prayed for can't happen overnight. We're bound to experience victories and defeats. But as we learn to love as He commands, we can set aside our petty differences, we can forgive and ask for forgiveness, and the world will know we are Christians by our love.
 Elmer Towns, The Gospel of John: Believe and Live (Old Tappan, New Jersey: Fleming H. Revell Company, 1990), p. 257.