When Peter told his readers that they had had been redeemed by through the precious blood of Christ, in 1 Peter 1:22-25 he urged them to therefore have a sincere, pure and fervent love for one another. This kind of love would be evidence that they had been made new (born again) through the Word of God which they had received and believed. Love for others will also be the main evidence that we also belong to Jesus and know the depth and the value of his redeeming love.