Although the Apostle Paul was God's chosen gospel messenger to the Gentiles (Acts 26:17-18), he and his team were humble.  They considered themselves equal to their brothers and sisters in Christ, and not too proud to ask for their help.  In particular, they asked that the church in Thessalonica would pray for them as they faced danger for the sake of Jesus (1 Thessalonians 3:6-8).  It was a practical example of what he emphasised to various churches (Romans 16:2); he stood with them, and also asked them to stand with him … and with each other.
 
The godly affection within God's family for each other should be expressed warmly but appropriately, respecting that each believer they embraced belonged to the Lord (1 Corinthians 16:19-20).  Their relationships should be holy, and not used for business or personal advantage, but to enhance the reality that they stood together in Christ - even though the world and devil would try to separate them from each other and from Jesus.
 
But just standing together was inadequate spiritual protection.  Yes, they were linking their shields of faith together like squads of Roman soldiers (Ephesians 6:10-18).  But they also had to make their decisions based on what God said to them, and not just on a consensus of human wisdom.  So, Paul commanded that his letter would be read aloud in the church.  He expected that the leaders would ensure that the believers put it into practice (Hebrews 13:17).  In that way, they would understand and experience the grace of the Lord Jesus together.
 
True fellowship involves believers choosing to belong to each other, as well as to the Lord.  This is demonstrated as believers mutually admit their weakness, encouraging each other to be embraced and empowered by the Lord.  'Going to church' is not the same as 'being the church' together.  A ritual of religious observance, without truly loving relationships, is spiritually empty.  Substituting human values of relationship or using people for personal advantage is wrong.  We must learn to stand together by repenting of ungodliness and letting the Lord lead us by His Spirit according to His Word.  As we obey Him, we are moulded into the right shape for fellowship with Him, and our brothers and sisters (Philippians 2:1-4).  Then we can be real with each other, pray for one another, and stand firm in the Lord together - so that we can resist the worst that Satan would throw at us and be satisfied by His grace.