'Convinced' in the Bible

but so that the world may know [without any doubt] that I love the Father, I do exactly as the Father has commanded Me [and act in full agreement with Him]. Get up, let us go from here.

For the words which You gave Me I have given them; and they received and accepted them and truly understood [with confident assurance] that I came from You [from Your presence], and they believed [without any doubt] that You sent Me.

that they all may be one; just as You, Father, are in Me and I in You, that they also may be one in Us, so that the world may believe [without any doubt] that You sent Me.

So the other disciple, who had reached the tomb first, went in too; and he saw [the wrappings and the face-cloth] and believed [without any doubt that Jesus had risen from the dead].