Paul can't wait to get in touch with these people, either by himself or through Timothy. The idea seems to be for them not to think that they are alone, but that there are people who care about them and want the best for them.
This relationship did not come out of the blue. It was long-term coming. It began when Paul spoke to them of the new life in Christ, and they believed. Once they believed, they were helped to grow in Christ. That should be normative. People should be helped to grow in Christ when they become believers. And that is the whole point of the church, where we come to be built up into the image of Christ.
Everything in the church should be conceived as moving in that direction. When the church in Corinth was overemphasizing tongues as part of worship, Paul drew their attention to the main thing.
but in the church I want to speak five words with my mind to instruct others, rather than ten thousand words in a tongue. (1 Corinthians 14:19)
The main thing is for us to be built up into Christ, and that comes in the company of other believers (2 Timothy 2:22), since we are the body of Christ, meaning as individual members we need what the other parts supply (1 Corinthians 12:12-27).
It does not matter what name you call that church; we need to know if what is being proclaimed is the milk of the word of God (1 Peter 2:2), not so much what is exciting or what appeals to the flesh, just the truth, the whole truth, and nothing but the truth.
So we need one another.
But keep away from youthful passions, and pursue righteousness, faithfulness, love, and peace, in company with others who call on the Lord from a pure heart. (2 Timothy 2:22)
Paul is saying that Timothy should avoid something and pursue something else. But he does not recommend doing it alone. And it is not good if we are in the company of those who do not emphasize keeping away from youthful passions, and the pursuit of righteousness, faithfulness, love, and peace, mixed with calling upon God from a pure heart. It is not good.
In short, we are supposed to be built up into Christ. But my point is this kind of constant interaction among believers is necessary and important, even compulsory.
But our fellowship with one another is based on our fellowship with the Lord.
But if we walk in the light as he himself is in the light, we have fellowship with one another and the blood of Jesus his Son cleanses us from all sin. (1 John 1:7)
The way this is thought about is that there is a vertical relationship with God and a horizontal relationship with one another.
There is a problem when the emphasis is just about fellowship with one another, and the Lord is removed from that interaction. So we have gossip, complaining, and just seeing how the other person will serve you. We are not seeing the value in others, but seeing how we can add value to others.
...seek to abound in order to strengthen the church. (1 Corinthians 14:12b)
It needs to be clear what we are doing here, and the connection between believers must be stirred towards Christ's glorification.
You can't have a gathering for gathering's sake. You shouldn't attend church solely to include it on your resume. It has to be because you can benefit others, and others can benefit you in strengthening your vertical relationship with God, and our horizontal relationship with one another will be impacted also as it impacts your vertical relationship with God, in an ongoing mutual reinforcement loop to the glory of God.
Simply stated: our fellowship with one another should reinforce our fellowship with God, and our fellowship with God reinforces our fellowship with one another. Everything must be done to the glory of God. And I am not even exaggerating. It is the way it should be, the way it has to be, the way it must be. There is no alternative.
And let us take thought of how to spur one another on to love and good works, not abandoning our own meetings, as some are in the habit of doing, but encouraging each other, and even more so because you see the day drawing near. (Hebrews 10:24-25)
So church is not just to hang out, not a social gathering, not to impress people that you have come, not a means to a selfish end. It's where love should be fostered, but love in and of Christ, with a priority for the souls of people, and the valuation of what is spiritual and the transformation that Christ brings, where the seed of the word is sown for a harvest of goodness and godliness (James 3:18).
From Addiction to Freedom by Favour Oyinloye
