What a joy it has been to study the way God has saved us through adoption into his family (Gal 4:1-7, Rom 8:15-17). C.J. Mahaney was right in his recent message on adoption that meditating on this truth of Scripture will lead to assurance of God's love, peace of conscience, joy in the Holy Spirit, and I believe, increase of grace.
All Christians doubt, at times, whether it's possible that the Father really loves us as much as he loves his only begotten Son, Jesus. Could he love his adopted children as much as he does his only begotten Son?
My experience as a father of adopted and biological children is that there is no difference in the love I have for them. Whether through adoption or birth, they are all part of my family, and being in the family is what counts.
If you are in the family of God, you are loved as much as Jesus himself is loved by the Father. Believe it! Rejoice in it!