Christians are sons of God, not servants
One of the wonderful benefits we have as Christians is to be sons of God. Trusting in Jesus is not only a matter of having our sins forgiven, though it certainly includes that. It also means that we are adopted as sons of God. We are in God’s family, loved, secure, and with a certain future hope.
By the way, men and women can be called sons of God in this sense; it is not sexist to say this. Paul uses ‘sons of God’ and not ‘children of God’ in Galatians 4:5 because, in the ancient world, only the sons inherited from their fathers. All Christians inherit security and hope and much more from God our Father, whether we are male or female. So there is a way in which women can also be sons of God!
Paul describes some of the benefits of being a son of God in Galatians 4:6:
And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!”
All sons of God, all Christians, have the Holy Spirit in our hearts. The Spirit has a range of functions that we read about in the NT, from convicting us of sin to assuring us of our salvation. What Paul focussed on here is that the Spirit makes us cry “Abba! Father!”. Abba is the personal form of father, the kind of word a child would call their father at home, maybe something like ‘Dad’. We who are sons of God can call God by a personal, intimate name, for we have a close relationship, we are loved and secure in God’s family.
Galatians 4 contrasts this with the reality of being a slave or a servant of a household. Servants might be highly valued. They might work hard with the dream of pleasing their master, or the fear of disappointing their master. Yet the best they can hope for is thanks and continued employment; there is no ultimate security in being a servant. You might work hard but you don’t have the security and intimacy a son has.
Christians are sons of God, not servants. We do want to work hard to honour our Father, sure. But we are not doing so out of fear or duty or an attempt to win God’s love. We are already loved deeply because of Jesus. We are secure with a future that is certain. We can live lives that bring honour on the family from this position of security.
Don’t fall back into thinking like a servant. God loves you deeply if you trust in Jesus. You don’t need to fear his rejection. You should feel the joy of being one of God’s people. Let’s honour our Father with joyful lives worthy of being one of His sons.