It is common understanding that for an individual to believe or feel that something is true does not in itself imply that the something is indeed true. Truth is something to be understood outside of our own experience. It is true whether we believe it or not.
For example, it is true that objects in the dark are still there even if we cannot hear or see them. A statement that that implies that when in the absence of light an object no longer exists is false and can be proven so by someone reaching out into the dark to touch that object.
Validity focuses not upon whether the conclusion is true or false but rather on whether the process (argument) leading up to and supporting the conclusion is free from mistakes.
The following for example, shows how an argument can have a true conclusion but yet still be invalid.
Premise: The Sun is yellow
Premise: Fire is yellow
Premise: Fire is hot
Conclusion: Therefore the sun is hot
In this example, the conclusion is true yet the process is invalid as it proposes that a reason for the sun being hot is that it is yellow.
In the search for truth it is most important that both the conclusion is true and the supporting argument is valid. A valid argument is helpful for ensuring that ones own understanding of the truth is supported by reason as well as for pursuading others to accept and agree with your conclusions of what is true.