Albert Barnes Commentary 1 Thessalonians 2:8

"even so, being affectionately desirous of you, we were well pleased to impart unto you, not the gospel of God only, but also our own souls, because ye were become very dear to us." — 1 Thessalonians 2:8 (ASV)

So, being affectionately desirous of you. The word translated "being affectionately desirous," imeirw, occurs nowhere else in the New Testament. It means to long after, to have a strong affection for. The meaning here is that Paul was so strongly attached to them that he would have been willing to lay down his life for them.

We were willing to have imparted to you. To have given or communicated (Romans 1:11).

Not the gospel of God only. To be willing to communicate the knowledge of the gospel was in itself a strong proof of love, even if it involved no self-denial or hazard in doing so. We demonstrate a decided love for someone when we tell them of the way of salvation and urge them to accept it. We show strong interest in one who is in danger when we tell them of a way of escape, or for one who is sick when we tell them of a medicine that will restore them; but we manifest a much higher love when we tell a lost and ruined sinner of the way in which they may be saved. There is no method in which we can show so strong an interest in our fellow human beings, and so much true benevolence for them, as to go to them and tell them of the way by which they may be rescued from everlasting ruin.

But also our own souls. Or rather lives—qucav. Matthew 6:25; Matthew 20:28; Luke 12:22–23; Mark 3:4.

This does not mean that the apostle was willing to be damned, or to lose his soul in order to save them; but that, if it had been necessary, he would have been ready to lay down his life. See John 3:16. We ought to lay down our lives for the brethren. Compare John 15:13.

His object seems to be to assure them that he did not leave them from any lack of love for them, or from the fear of being put to death. It was done from the strong conviction of duty. He appears to have left them because he could no longer remain without exposing others to danger, and without the certainty that there would be continued disturbances. See Acts 17:9-10.