These words from the French Reformed Baptisimal liturgy are beautiful:
Little child, for you Jesus Christ has come, he has fought, he has suffered. For you he entered the shadow of Gethsemane and the horror of Calvary. For you he uttered the cry "It is finished!" For you he rose from the dead and ascended into heaven and there intercedes - for you, little child, even though you do not know it. But in this way the word of the Gospel becomes true. "We love him, because he first loved us."
That describes the foundation of my belief that it is right to baptise infants. As James Torrance expands:
The work of salvation is from beginning to end the work of God. Baptism is the sign of what the triune God does. God forgives, God cleanses, God regenerates, God adopts, God sends the Spirit of his Son into our hearts whereby we cry "Abba, Father." Our response to this is to say amen in faith- our passive recipient response. There is nothing more passive than dying, being buried, being baptised.
Two things are important here: (a) Christ did not die for adults only! He died for adults and children..."Little child for you..." (b) God's grace is not conditioned by anything in us, not even by our faith! Nevertheless, baptism must always be an act of faith in the Christ who died for us and for our children. It is not a sign of our faith, but of the Christ in whom we believe [...] "...for you, little child, even though you do not know it..."
(pp. 76-80, James B Torrance, Worship, Community and the Triune God of Grace)