The Outward Evidence of Salvattion
Throughout history, there have been many comments made about the external evidence of salvation. Most of these comments are not scriptural. For example, there are some who say "I know I'm saved because I go to church every Sunday." Going to church has nothing to do with salvation, and certainly is no evidence. There are plenty of unsaved who are nonetheless "religious", and go to church faithfully. Some say they're saved because they've been baptized. Baptism doesn't save.
Fortunately, we have several scriptures that speak to the issue of "external evidence". Once again we point out that at the moment of salvation, we are baptized by Jesus with the Holy Spirit (see What is Salvation) and the Holy Spirit baptizes us into the body of Christ, His Church (1 Cor.12:13). This selfsame Holy Spirit then begins a work in our lives. Indeed, it is a lifelong work. What happens is the Holy Spirit begins to cultivate Christ in our hearts and minds, and from this cultivation comes fruit. In Galatians 5:22 we see "but the fruit of the Spirit is love, joy, peace, longsuffering (patience), gentleness, goodness, faith, meekness, temperance (self-control): against such there is no law".
Much more could be said, but I think this scripture speaks directly to the issue of evidence. When we are His, this fruit will come forth in our lives. It may take time, and it most assuredly will take practice. A lifetime of practice. We will fall, we will stumble, we will fail, but by the grace of God we will get up, and with His help we will try again until He completes His perfect work in us.
It is hard to say which one of the fruits is most important, but again scripture points the direction. The first fruit mentioned is love, and 1 Cor. 13 lets us know how important it is in Gods plans. Jesus' sacrifice on the cross is the ultimate expression of that love.
"Though I speak with the tongues of men and of angels, and have not love, I am become as sounding brass, or a tinkling cymbal. And though I have the gift of prophecy, and understand all mysteries, and all knowledge: and though I have all faith, so that I could remove mountains, and have not love, I am nothing. And though I bestow all my goods to feed the poor, and though I give my body to be burned, and have not love, it profits me nothing. Love suffers long, and is kind; love envies not; love does not build itself up, or get a swelled head, does not behave itself unseemly, does not look after her own things, is not easily angered, and does not think evil; it does not rejoice in sin, but rejoices in the truth; Love bears all things, believes all things, hopes all things, endures all things. Love never fails; but where there are prophecies, they shall fail; where there are tongues, they shall cease; where there is knowledge, it shall vanish away. For we know in part, and we prophesy in part. But when that which is perfect is come, then that which is in part shall be done away with. When I was a child, I spoke as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things. For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am know. And now abides faith, hope, and love, these three; but the greatest of these is love."